code: public boolean addContributor(String projectId, String name, String email, String language){
          ResponseWrapper wrapper = service.addProjectMember(Action.ADD_CONTRIBUTOR, apiKey, projectId, name, email, language, 0);
          ApiUtils.checkResponse(wrapper.response);
          return "200".equals(wrapper.response.code);
      }
docs: Add/create a contributor for a language of a project
  
  @param projectId id of the project
  @param name name of the contributor
  @param email email of the contributor
  @param language language for the contributor
  @return boolean if the contributor has been added