code: def parse_declaration_expressn_memberaccess(self, lhsAST, rhsAST, es):
          
          if isinstance(lhsAST, wdl_parser.Terminal):
              es = es + lhsAST.source_string
          elif isinstance(lhsAST, wdl_parser.Ast):
              raise NotImplementedError
          elif isinstance(lhsAST, wdl_parser.AstList):
              raise NotImplementedError
  
          es = es + '_'
  
          if isinstance(rhsAST, wdl_parser.Terminal):
              es = es + rhsAST.source_string
          elif isinstance(rhsAST, wdl_parser.Ast):
              raise NotImplementedError
          elif isinstance(rhsAST, wdl_parser.AstList):
              raise NotImplementedError
  
          return es
docs: Instead of "Class.variablename", use "Class.rv('variablename')".
  
          :param lhsAST:
          :param rhsAST:
          :param es:
          :return: