code: public void create(String personGroupId, CreatePersonGroupsOptionalParameter createOptionalParameter) {
          createWithServiceResponseAsync(personGroupId, createOptionalParameter).toBlocking().single().body();
      }
docs: Create a new person group with specified personGroupId, name and user-provided userData.
  
  @param personGroupId Id referencing a particular person group.
  @param createOptionalParameter the object representing the optional parameters to be set before calling this API
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws APIErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent