code: def make_ref(self, branch):
          
          master_sha = self.get_ref(self.master_upstream)
          if not isinstance(master_sha, str):
              return self.ProxyError(
                  404,
                  "The default branch from which to checkout is either not available or does not exist",
                  step="make_ref"
              )
  
          params = {
            "ref": "refs/heads/{branch}".format(branch=branch),
            "sha": master_sha
          }
          uri = "{api}/repos/{origin}/git/refs".format(
              api=self.github_api_url,
              origin=self.origin
          )
          data = self.request("POST", uri, data=params)
  
          if data.status_code == 201:
              data = json.loads(data.content.decode("utf-8"))
              return data["object"]["sha"]
          else:
              decoded_data = json.loads(data.content.decode("utf-8"))
              return self.ProxyError(
                  data.status_code, (decoded_data, "message"),
                  step="make_ref", context={
                      "uri": uri,
                      "params": params
                  }
              )
docs: Make a branch on github
  
          :param branch: Name of the branch to create
          :return: Sha of the branch or self.ProxyError