docs: def configure_rpc(cls, scheme=None):
          """ Get methods from scheme. """
          scheme = scheme or cls._meta.scheme
  
          if not scheme:
              return
  
          if isinstance(scheme, basestring):
              scheme = importlib.import_module(scheme)
  
          cls.scheme_name = scheme.__name__
  
          methods = getattr(scheme, '__all__', None) \
              or [m for m in dir(scheme) if not m.startswith('_')]
  
          for mname in methods:
              method = getattr(scheme, mname)
              if hasattr(method, '__call__'):
                  cls.methods["{0}.{1}".format(
                      cls.scheme_name, method.__name__)] = method