code: def _post_subject(self, body):
          
          assert isinstance(body, (list)), "POST requires body to be a list"
  
          uri = self._get_subject_uri()
          return self.service._post(uri, body)
docs: Create new subjects and associated attributes.
  
          Example:
  
              acs.post_subject([
                  {
                      "subjectIdentifier": "/role/evangelist",
                      "parents": [],
                      "attributes": [
                          {
                              "issuer": "default",
                              "name": "role",
                              "value": "developer evangelist",
                          }
                      ]
                  }
              ])
  
          The issuer is effectively a namespace, and in policy evaluations
          you identify an attribute by a specific namespace.  Many examples
          provide a URL but it could be any arbitrary string.
  
          The body is a list, so many subjects can be added at the same time.