code: def _get_unique_variable_name(vname, variables):
      '''Get a unique variable name.
  
      Args:
          vname(str): A candidate name.
          variable(OrderedDict of str and Variable)
  
      Returns: str
          A unique variable name
      '''
      count = 2
      vname_base = vname
      while vname in variables:
          vname = '{}_{}'.format(vname_base, count)
          count += 1
      return vnamf _get_unique_variable_name(vname, variables):
      '''Get a unique variable name.
  
      Args:
          vname(str): A candidate name.
          variable(OrderedDict of str and Variable)
  
      Returns: str
          A unique variable name
      '''
      count = 2
      vname_base = vname
      while vname in variables:
          vname = '{}_{}'.format(vname_base, count)
          count += 1
      return vname
docs: Get a unique variable name.
  
      Args:
          vname(str): A candidate name.
          variable(OrderedDict of str and Variable)
  
      Returns: str
          A unique variable name