code: def get_matcher(self, reqt):
          
          try:
              matcher = self.scheme.matcher(reqt)
          except UnsupportedVersionError:  # pragma: no cover
              # XXX compat-mode if cannot read the version
              name = reqt.split()[0]
              matcher = self.scheme.matcher(name)
          return matcher
docs: Get a version matcher for a requirement.
          :param reqt: The requirement
          :type reqt: str
          :return: A version matcher (an instance of
                   :class:`distlib.version.Matcher`).