class_docstr: Represents a match of a variable in the grammar.
  
  :param varname: (string) Name of the variable.
  :param value: (string) Value of this variable.
  :param slice: (start, stop) tuple, indicating the position of this variable
                in the input string.
code: def __repr__(self):
      return "%s(%r, %r)" % (
          self.__class__.__name__,
          self.varname,
          self.value,
      )
  
imports: from __future__ import unicode_literals
  import re
  from six.moves import range
  from .regex_parser import Any, Sequence, Regex, Variable, Repeat, Lookahead
  from .regex_parser import parse_regex, tokenize_regex
label_desc: Use image node_id 2 for calling the MatchVariable obj's underlying member method code with example usage: obj.__repr__() and returns: unknown