code: def _make_interpolation_node(self, tag_type, tag_key, leading_whitespace):
          
          # TODO: switch to using a dictionary instead of a bunch of ifs and elifs.
          if tag_type == '!':
              return _CommentNode()
  
          if tag_type == '=':
              delimiters = tag_key.split()
              self._change_delimiters(delimiters)
              return _ChangeNode(delimiters)
  
          if tag_type == '':
              return _EscapeNode(tag_key)
  
          if tag_type == '&':
              return _LiteralNode(tag_key)
  
          if tag_type == '>':
              return _PartialNode(tag_key, leading_whitespace)
  
          raise Exception("Invalid symbol for interpolation tag: %s" % repr(tag_type))
docs: Create and return a non-section node for the parse tree.