code: def is_conflicting(self):
          
          # unknown installed version is also considered conflicting
          if self.installed_version == self.UNKNOWN_VERSION:
              return True
          ver_spec = (self.version_spec if self.version_spec else '')
          req_version_str = '{0}{1}'.format(self.project_name, ver_spec)
          req_obj = pkg_resources.Requirement.parse(req_version_str)
          return self.installed_version not in req_obj
docs: If installed version conflicts with required version