code: @Override
  	public ClosableIterator<Tuple> callStoredProcedure(String storedProcedureName, ProcedureQueryParameters params, TupleContext tupleContext) {
  		validate( params );
  		StringBuilder commandLine = createCallStoreProcedureCommand( storedProcedureName, params );
  		Document result = callStoredProcedure( commandLine );
  		Object resultValue = result.get( "retval" );
  		List<Tuple> resultTuples = extractTuples( storedProcedureName, resultValue );
  		return CollectionHelper.newClosableIterator( resultTuples );
  	}
docs: In MongoDB the equivalent of a stored procedure is a stored Javascript.
  
  @param storedProcedureName name of stored procedure
  @param params query parameters
  @param tupleContext the tuple context
  
  @return the result as a {@link ClosableIterator}