docs: public Object getUserIdOrUsername(Object obj) throws GitLabApiException {
  
          if (obj == null) {
              throw (new RuntimeException("Cannot determine ID or username from null object"));
          } else if (obj instanceof Integer) {
              return (obj);
          } else if (obj instanceof String) {
              return (urlEncode(((String) obj).trim()));
          } else if (obj instanceof User) {
  
              Integer id = ((User) obj).getId();
              if (id != null && id.intValue() > 0) {
                  return (id);
              }
  
              String username = ((User) obj).getUsername();
              if (username != null && username.trim().length() > 0) {
                  return (urlEncode(username.trim()));
              }
  
              throw (new RuntimeException("Cannot determine ID or username from provided User instance"));
  
          } else {
  
              throw (new RuntimeException("Cannot determine ID or username from provided " + obj.getClass().getSimpleName() +
                      " instance, must be Integer, String, or a User instance"));
          }
      }