@ Override public boolean validate ( Graph < K , VV , EV > graph ) throws Exception { DataSet < Tuple1 < K >> edgeIds = graph . getEdges ( ) . flatMap ( new MapEdgeIds <> ( ) ) . distinct ( ) ; DataSet < K > invalidIds = graph . getVertices ( ) . coGroup ( edgeIds ) . where ( 0 ) . equalTo ( 0 ) . with ( new GroupInvalidIds <> ( ) ) . first ( 1 ) ; return invalidIds . map ( new KToTupleMap <> ( ) ) . count ( ) == 0 ; }
Checks that the edge set input contains valid vertex Ids i . e . that they also exist in the vertex input set .