code: def create_user(self, username, password):
          
          user_id = "org.couchdb.user:" + username
          res = self["_users"].resource.put(
              user_id, body=json.dumps({
                  "_id": user_id,
                  "name": username,
                  "roles": [],
                  "type": "user",
                  "password": password,
                  "farms": []
              })
          )
          if res[0] == 409:
              raise RuntimeError(
                  'The username "{}" is already taken'.format(username)
              )
          elif res[0] != 201:
              raise RuntimeError(
                  "Failed to create user ({}): {}".format(
                      res.status_code, res.content
                  )
              )
docs: Creates a user in the CouchDB instance with the username `username` and
          password `password`