code: public <M> Graph<K, VV, EV> runScatterGatherIteration(
  			ScatterFunction<K, VV, M, EV> scatterFunction,
  			org.apache.flink.graph.spargel.GatherFunction<K, VV, M> gatherFunction,
  			int maximumNumberOfIterations) {
  
  		return this.runScatterGatherIteration(scatterFunction, gatherFunction,
  				maximumNumberOfIterations, null);
  	}
docs: Runs a ScatterGather iteration on the graph.
  No configuration options are provided.
  
  @param scatterFunction the scatter function
  @param gatherFunction the gather function
  @param maximumNumberOfIterations maximum number of iterations to perform
  
  @return the updated Graph after the scatter-gather iteration has converged or
  after maximumNumberOfIterations.