code: def inverse(self):
          
          if self.is_any():
              return None
          else:
              bounds = self._inverse(self.bounds)
              range = VersionRange(None)
              range.bounds = bounds
              return range
docs: Calculate the inverse of the range.
  
          Returns:
              New VersionRange object representing the inverse of this range, or
              None if there is no inverse (ie, this range is the any range).