code: def add_hookspecs(self, module_or_class):
          
          names = []
          for name in dir(module_or_class):
              spec_opts = self.parse_hookspec_opts(module_or_class, name)
              if spec_opts is not None:
                  hc = getattr(self.hook, name, None)
                  if hc is None:
                      hc = _HookCaller(name, self._hookexec, module_or_class, spec_opts)
                      setattr(self.hook, name, hc)
                  else:
                      # plugins registered this hook without knowing the spec
                      hc.set_specification(module_or_class, spec_opts)
                      for hookfunction in hc.get_hookimpls():
                          self._verify_hook(hc, hookfunction)
                  names.append(name)
  
          if not names:
              raise ValueError(
                  "did not find any %r hooks in %r" % (self.project_name, module_or_class)
              )
docs: add new hook specifications defined in the given module_or_class.
          Functions are recognized if they have been decorated accordingly.