org.apache.flink.graph.test.TestGraphUtils Java Examples

@Test
public void testCreateWithMapper() throws Exception {
	/*
	 * Test create() with edge dataset and a mapper that assigns the id as value
     */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongEdgeData(env),
		new AssignIdAsValueMapper(), env);

	DataSet<Vertex<Long, Long>> data = graph.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,1\n" +
		"2,2\n" +
		"3,3\n" +
		"4,4\n" +
		"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

/**
 * Test getDegrees() with an edge having a srcId and a trgId that does not exist in the vertex DataSet.
 */
@Test
public void testGetDegreesInvalidEdgeSrcTrgId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidSrcTrgData(env), env);

	try {
		graph.getDegrees().output(new DiscardingOutputFormat<>());
		env.execute();

		fail("graph.getDegrees() did not fail.");
	}
	catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

/**
 * Test getDegrees() with an edge having a srcId that does not exist in the vertex DataSet.
 */
@Test
public void testGetDegreesInvalidEdgeSrcId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidSrcData(env), env);

	try {
		graph.getDegrees().output(new DiscardingOutputFormat<>());
		env.execute();

		fail("graph.getDegrees() did not fail.");
	} catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

@Test
public void testWithCustomType() throws Exception {
	/*
	 * Test mapEdges() and change the value type to a custom type
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Edge<Long, DummyCustomType>> mappedEdges = graph.mapEdges(new ToCustomTypeMapper()).getEdges();
	List<Edge<Long, DummyCustomType>> result = mappedEdges.collect();

	expectedResult = "1,2,(T,12)\n" +
		"1,3,(T,13)\n" +
		"2,3,(T,23)\n" +
		"3,4,(T,34)\n" +
		"3,5,(T,35)\n" +
		"4,5,(T,45)\n" +
		"5,1,(T,51)\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithConstantValueMapper() throws Exception {
	/*
	 * Test create() with edge dataset with String key type
	 * and a mapper that assigns a double constant as value
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<String, Double, Long> graph = Graph.fromDataSet(TestGraphUtils.getStringLongEdgeData(env),
		new AssignDoubleConstantMapper(), env);

	DataSet<Vertex<String, Double>> data = graph.getVertices();
	List<Vertex<String, Double>> result = data.collect();

	expectedResult = "1,0.1\n" +
		"2,0.1\n" +
		"3,0.1\n" +
		"4,0.1\n" +
		"5,0.1\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testLowestWeightInNeighbor() throws Exception {
	/*
	 * Get the lowest-weight in-neighbor
	 * for each vertex
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithLowestOutNeighbor =
		graph.groupReduceOnEdges(new SelectMinWeightInNeighbor(), EdgeDirection.IN);
	List<Tuple2<Long, Long>> result = verticesWithLowestOutNeighbor.collect();

	expectedResult = "1,5\n" +
		"2,1\n" +
		"3,1\n" +
		"4,3\n" +
		"5,3\n";

	compareResultAsTuples(result, expectedResult);
}
 

/**
 * Test outDegrees() with an edge having a srcId that does not exist in the vertex DataSet.
 */
@Test
public void testOutDegreesInvalidEdgeSrcId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidSrcData(env), env);

	try {
		graph.outDegrees().output(new DiscardingOutputFormat<>());
		env.execute();

		fail("graph.outDegrees() did not fail.");
	} catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

@Test
public void testWithLessElements() throws Exception {
	/*
	 * Test joinWithVertices with the input DataSet passed as a parameter containing
	 * less elements than the vertex DataSet, but of the same type
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	Graph<Long, Long, Long> res = graph.joinWithVertices(graph.getVertices().first(3)
		.map(new VertexToTuple2Map<>()), new AddValuesMapper());

	DataSet<Vertex<Long, Long>> data = res.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,2\n" +
		"2,4\n" +
		"3,6\n" +
		"4,4\n" +
		"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testDifferenceVertices() throws Exception {
	/*Test  difference() method  by checking    the output  for getVertices()   on  the resultant   graph
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	Graph<Long, Long, Long> graph2 = Graph.fromDataSet(TestGraphUtils.getLongLongVertexDataDifference(env),
		TestGraphUtils.getLongLongEdgeDataDifference(env), env);

	graph = graph.difference(graph2);

	List<Vertex<Long, Long>> result = graph.getVertices().collect();

	expectedResult = "2,2\n" +
		"4,4\n" +
		"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testLowestWeightInNeighbor() throws Exception {
	/*
	 * Get the lowest-weight in-neighbor
	 * for each vertex
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithLowestOutNeighbor =
		graph.groupReduceOnEdges(new SelectMinWeightInNeighbor(), EdgeDirection.IN);
	List<Tuple2<Long, Long>> result = verticesWithLowestOutNeighbor.collect();

	expectedResult = "1,5\n" +
		"2,1\n" +
		"3,1\n" +
		"4,3\n" +
		"5,3\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithDifferentType() throws Exception {
	/*
	 * Test joinWithVertices with the input DataSet passed as a parameter containing
	 * less elements than the vertex DataSet and of a different type(Boolean)
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	Graph<Long, Long, Long> res = graph.joinWithVertices(graph.getVertices().first(3)
		.map(new ProjectIdWithTrue()), new DoubleIfTrueMapper());

	DataSet<Vertex<Long, Long>> data = res.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,2\n" +
		"2,4\n" +
		"3,6\n" +
		"4,4\n" +
		"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithDifferentType() throws Exception {
	/*
	 * Test joinWithVertices with the input DataSet passed as a parameter containing
	 * less elements than the vertex DataSet and of a different type(Boolean)
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	Graph<Long, Long, Long> res = graph.joinWithVertices(graph.getVertices().first(3)
		.map(new ProjectIdWithTrue()), new DoubleIfTrueMapper());

	DataSet<Vertex<Long, Long>> data = res.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,2\n" +
		"2,4\n" +
		"3,6\n" +
		"4,4\n" +
		"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithConstantValueMapper() throws Exception {
	/*
	 * Test create() with edge dataset with String key type
	 * and a mapper that assigns a double constant as value
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<String, Double, Long> graph = Graph.fromDataSet(TestGraphUtils.getStringLongEdgeData(env),
		new AssignDoubleConstantMapper(), env);

	DataSet<Vertex<String, Double>> data = graph.getVertices();
	List<Vertex<String, Double>> result = data.collect();

	expectedResult = "1,0.1\n" +
		"2,0.1\n" +
		"3,0.1\n" +
		"4,0.1\n" +
		"5,0.1\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testAllInNeighborsNoValue() throws Exception {
	/*
	 * Get the all the in-neighbors for each vertex except for the vertex with id 5.
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithAllInNeighbors =
		graph.groupReduceOnEdges(new SelectInNeighborsExceptFive(), EdgeDirection.IN);
	List<Tuple2<Long, Long>> result = verticesWithAllInNeighbors.collect();

	expectedResult = "1,5\n" +
		"2,1\n" +
		"3,1\n" +
		"3,2\n" +
		"4,3";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testAllInNeighborsWithValueGreaterThanTwo() throws Exception {
	/*
	 * Get the all the in-neighbors for each vertex that have a value greater than two.
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithAllInNeighbors =
		graph.groupReduceOnEdges(new SelectInNeighborsValueGreaterThanTwo(), EdgeDirection.IN);
	List<Tuple2<Long, Long>> result = verticesWithAllInNeighbors.collect();

	expectedResult = "3,1\n" +
		"3,2\n" +
		"4,3\n" +
		"5,3\n" +
		"5,4";

	compareResultAsTuples(result, expectedResult);
}
 

/**
 * Test groupReduceOnNeighbors() -NeighborsFunctionWithVertexValue-
 * with an edge having a trgId that does not exist in the vertex DataSet.
 */
@Test
public void testGroupReduceOnNeighborsWithVVInvalidEdgeTrgId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidTrgData(env), env);

	try {
		DataSet<Tuple2<Long, Long>> verticesWithSumOfOutNeighborValues =
				graph.groupReduceOnNeighbors(new SumAllNeighbors(), EdgeDirection.ALL);

		verticesWithSumOfOutNeighborValues.output(new DiscardingOutputFormat<>());
		env.execute();

		fail("Expected an exception.");
	} catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

@Test
public void testGetDegreesWithDisconnectedData() throws Exception {
	/*
	 * Test getDegrees() with disconnected data
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, NullValue, Long> graph =
		Graph.fromDataSet(TestGraphUtils.getDisconnectedLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, LongValue>> data = graph.outDegrees();
	List<Tuple2<Long, LongValue>> result = data.collect();

	expectedResult = "1,2\n" +
		"2,1\n" +
		"3,0\n" +
		"4,1\n" +
		"5,0\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testAddVertexExisting() throws Exception {
	/*
	 * Test addVertex() -- add an existing vertex
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

	graph = graph.addVertex(new Vertex<>(1L, 1L));

	DataSet<Vertex<Long, Long>> data = graph.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,1\n" +
			"2,2\n" +
			"3,3\n" +
			"4,4\n" +
			"5,5\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithTuple2ValueMapper() throws Exception {
	/*
	 * Test create() with edge dataset and a mapper that assigns a Tuple2 as value
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Tuple2<Long, Long>, Long> graph = Graph.fromDataSet(
		TestGraphUtils.getLongLongEdgeData(env), new AssignTuple2ValueMapper(), env);

	DataSet<Vertex<Long, Tuple2<Long, Long>>> data = graph.getVertices();
	List<Vertex<Long, Tuple2<Long, Long>>> result = data.collect();

	expectedResult = "1,(2,42)\n" +
		"2,(4,42)\n" +
		"3,(6,42)\n" +
		"4,(8,42)\n" +
		"5,(10,42)\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testWithDCustomValueMapper() throws Exception {
	/*
	 * Test create() with edge dataset and a mapper that assigns a custom vertex value
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, DummyCustomType, Long> graph = Graph.fromDataSet(
		TestGraphUtils.getLongLongEdgeData(env), new AssignCustomValueMapper(), env);

	DataSet<Vertex<Long, DummyCustomType>> data = graph.getVertices();
	List<Vertex<Long, DummyCustomType>> result = data.collect();

	expectedResult = "1,(F,0)\n" +
		"2,(F,1)\n" +
		"3,(F,2)\n" +
		"4,(F,3)\n" +
		"5,(F,4)\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testGetDegreesWithDisconnectedData() throws Exception {
	/*
	 * Test getDegrees() with disconnected data
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, NullValue, Long> graph =
		Graph.fromDataSet(TestGraphUtils.getDisconnectedLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, LongValue>> data = graph.outDegrees();
	List<Tuple2<Long, LongValue>> result = data.collect();

	expectedResult = "1,2\n" +
		"2,1\n" +
		"3,0\n" +
		"4,1\n" +
		"5,0\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testEdgesIds() throws Exception {
	/*
	 * Test getEdgeIds()
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> data = graph.getEdgeIds();
	List<Tuple2<Long, Long>> result = data.collect();

	expectedResult = "1,2\n" + "1,3\n" +
		"2,3\n" + "3,4\n" +
		"3,5\n" + "4,5\n" +
		"5,1\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testAllNeighborsWithValueGreaterThanFour() throws Exception {
	/*
	 * Get the all the neighbors for each vertex that have a value greater than four.
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithAllNeighbors =
		graph.groupReduceOnEdges(new SelectNeighborsValueGreaterThanFour(), EdgeDirection.ALL);
	List<Tuple2<Long, Long>> result = verticesWithAllNeighbors.collect();

	expectedResult = "5,1\n" +
		"5,3\n" +
		"5,4";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testRemoveInvalidEdge() throws Exception {
	/*
	 * Test removeEdge() -- invalid edge
	 */

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);
	graph = graph.removeEdge(new Edge<>(6L, 1L, 61L));

	DataSet<Edge<Long, Long>> data = graph.getEdges();
	List<Edge<Long, Long>> result = data.collect();

	expectedResult = "1,2,12\n" +
			"1,3,13\n" +
			"2,3,23\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

	compareResultAsTuples(result, expectedResult);
}
 

/**
 * Test groupReduceOnNeighbors() -NeighborsFunction-
 * with an edge having a srcId that does not exist in the vertex DataSet.
 */
@Test
public void testGroupReduceOnNeighborsInvalidEdgeSrcId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidTrgData(env), env);

	try {
		DataSet<Tuple2<Long, Long>> verticesWithSumOfAllNeighborValues =
				graph.reduceOnNeighbors(new SumNeighbors(), EdgeDirection.ALL);

		verticesWithSumOfAllNeighborValues.output(new DiscardingOutputFormat<>());
		env.execute();
	} catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

@Test
public void testAddVertex() throws Exception {
	/*
	 * Test addVertex() -- simple case
	 */

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);

	graph = graph.addVertex(new Vertex<>(6L, 6L));

	DataSet<Vertex<Long, Long>> data = graph.getVertices();
	List<Vertex<Long, Long>> result = data.collect();

	expectedResult = "1,1\n" +
			"2,2\n" +
			"3,3\n" +
			"4,4\n" +
			"5,5\n" +
			"6,6\n";

	compareResultAsTuples(result, expectedResult);
}
 

/**
 * Test inDegrees() with an edge having a trgId that does not exist in the vertex DataSet.
 */
@Test
public void testInDegreesInvalidEdgeTrgId() throws Exception {

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	env.setParallelism(PARALLELISM);
	env.getConfig().disableSysoutLogging();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeInvalidTrgData(env), env);

	try {
		graph.inDegrees().output(new DiscardingOutputFormat<>());
		env.execute();

		fail("graph.inDegrees() did not fail.");
	} catch (Exception e) {
		// We expect the job to fail with an exception
	}
}
 

@Test
public void testUndirected() throws Exception {
	/*
	 * Test getUndirected()
	 */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Edge<Long, Long>> data = graph.getUndirected().getEdges();
	List<Edge<Long, Long>> result = data.collect();

	expectedResult = "1,2,12\n" + "2,1,12\n" +
		"1,3,13\n" + "3,1,13\n" +
		"2,3,23\n" + "3,2,23\n" +
		"3,4,34\n" + "4,3,34\n" +
		"3,5,35\n" + "5,3,35\n" +
		"4,5,45\n" + "5,4,45\n" +
		"5,1,51\n" + "1,5,51\n";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testAllNeighborsWithValueGreaterThanFour() throws Exception {
	/*
	 * Get the all the neighbors for each vertex that have a value greater than four.
        */
	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
		TestGraphUtils.getLongLongEdgeData(env), env);

	DataSet<Tuple2<Long, Long>> verticesWithAllNeighbors =
		graph.groupReduceOnEdges(new SelectNeighborsValueGreaterThanFour(), EdgeDirection.ALL);
	List<Tuple2<Long, Long>> result = verticesWithAllNeighbors.collect();

	expectedResult = "5,1\n" +
		"5,3\n" +
		"5,4";

	compareResultAsTuples(result, expectedResult);
}
 

@Test
public void testRemoveInvalidEdge() throws Exception {
	/*
	 * Test removeEdge() -- invalid edge
	 */

	final ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();

	Graph<Long, Long, Long> graph = Graph.fromDataSet(TestGraphUtils.getLongLongVertexData(env),
			TestGraphUtils.getLongLongEdgeData(env), env);
	graph = graph.removeEdge(new Edge<>(6L, 1L, 61L));

	DataSet<Edge<Long, Long>> data = graph.getEdges();
	List<Edge<Long, Long>> result = data.collect();

	expectedResult = "1,2,12\n" +
			"1,3,13\n" +
			"2,3,23\n" +
			"3,4,34\n" +
			"3,5,35\n" +
			"4,5,45\n" +
			"5,1,51\n";

	compareResultAsTuples(result, expectedResult);
}