docs: def _is_version_range(req):
      """Returns true if requirements specify a version range."""
  
      assert len(req.specifier) > 0
      specs = list(req.specifier)
      if len(specs) == 1:
          # "foo > 2.0" or "foo == 2.4.3"
          return specs[0].operator != '=='
      else:
          # "foo > 2.0, < 3.0"
          return True