// data source for the edges
FileDataSource edges = new FileDataSource(new CsvInputFormat(' ', LongValue.class, LongValue.class), edgeInput, "Edges");
// join workset (changed vertices) with the edges to propagate changes to neighbors
JoinOperator joinWithNeighbors = JoinOperator.builder(new NeighborWithComponentIDJoin(), LongValue.class, 0, 0)
.input1(iteration.getWorkset())
.input2(edges)
.name("Join Candidate Id With Neighbor")
.build();