code: private static DataSet<Centroid> getCentroidDataSet(ParameterTool params, ExecutionEnvironment env) {
  		DataSet<Centroid> centroids;
  		if (params.has("centroids")) {
  			centroids = env.readCsvFile(params.get("centroids"))
  				.fieldDelimiter(" ")
  				.pojoType(Centroid.class, "id", "x", "y");
  		} else {
  			System.out.println("Executing K-Means example with default centroid data set.");
  			System.out.println("Use --centroids to specify file input.");
  			centroids = KMeansData.getDefaultCentroidDataSet(env);
  		}
  		return centroids;
  	}
docs: *************************************************************************