code: def get_upstream(self, type_):
          '''Return self, or an upstream, that has the given class type.
          This is typically used to find upstream s that impoement the RemoteInterface
          '''
  
          if isinstance(self, type_):
              return self
          elif self.upstream and isinstance(self.upstream, type_):
              return self.upstream
          elif self.upstream:
              return self.upstream.get_upstream(type_)
          else:
              return Nonf get_upstream(self, type_):
          '''Return self, or an upstream, that has the given class type.
          This is typically used to find upstream s that impoement the RemoteInterface
          '''
  
          if isinstance(self, type_):
              return self
          elif self.upstream and isinstance(self.upstream, type_):
              return self.upstream
          elif self.upstream:
              return self.upstream.get_upstream(type_)
          else:
              return None
docs: Return self, or an upstream, that has the given class type.
          This is typically used to find upstream s that impoement the RemoteInterface