code: def get_package_manager(self, dep_t):
          
          mgrs = managers.get(dep_t, [])
          for manager in mgrs:
              if manager.works():
                  return manager
          if not mgrs:
              err = 'No package manager for dependency type "{dep_t}"'.format(dep_t=dep_t)
              raise exceptions.NoPackageManagerException(err)
          else:
              mgrs_nice = ', '.join([mgr.__name__ for mgr in mgrs])
              err = 'No working package manager for "{dep_t}" in: {mgrs}'.format(dep_t=dep_t,
                                                                                mgrs=mgrs_nice)
              raise exceptions.NoPackageManagerOperationalException(err)
docs: Choose proper package manager and return it.