code: def _parse_vars(self, tokens):
          
          key_values = {}
          for token in tokens:
              if token.startswith('#'):
                  # End parsing if we encounter a comment, which lasts
                  # until the end of the line.
                  break
              else:
                  k, v = token.split('=', 1)
                  key = k.strip()
                  key_values[key] = v.strip()
          return key_values
docs: Given an iterable of tokens, returns variables and their values as a
          dictionary.
  
          For example:
              ['dtap=prod', 'comment=some comment']
          Returns:
              {'dtap': 'prod', 'comment': 'some comment'}