code: public FaunusPipeline v(final long... ids) {
          this.state.assertNotLocked();
          this.state.assertNoProperty();
  
          this.state.set(Vertex.class);
          this.state.incrStep();
  
          this.compiler.addMap(VertexMap.Map.class,
                  NullWritable.class,
                  FaunusVertex.class,
                  VertexMap.createConfiguration(ids));
  
          makeMapReduceString(VertexMap.class);
          return this;
      }
docs: Start a traversal at the vertices identified by the provided ids.
  
  @param ids the long ids of the vertices to start the traversal from
  @return the extended FaunusPipeline