docs: def r_update(self):
          """ Updates a fork Master
  
              - Check the ref of the origin repository
              - Patch reference of fork repository
              - Return status to Perseids
  
          :return: JSON Response with status_code 201 if successful.
          """
  
          # Getting Master Branch
          upstream = self.get_ref(self.master_upstream, origin=self.upstream)
          if isinstance(upstream, bool):
              return (ProxyError(
                  404, "Upstream Master branch '{0}' does not exist".format(self.master_upstream),
                  step="get_upstream_ref"
              )).response()
          elif isinstance(upstream, self.ProxyError):
              return upstream.response()
  
          # Patching
          new_sha = self.patch_ref(upstream)
          if isinstance(new_sha, self.ProxyError):
              return new_sha.response()
  
          self.logger.info("Updated repository {} to sha {}".format(self.origin, new_sha), extra={"former_sha": upstream})
          return jsonify({
              "status": "success",
              "commit": new_sha
          })