code: public Observable<RegexEntityExtractor> getRegexEntityEntityInfoAsync(UUID appId, String versionId, UUID regexEntityId) {
          return getRegexEntityEntityInfoWithServiceResponseAsync(appId, versionId, regexEntityId).map(new Func1<ServiceResponse<RegexEntityExtractor>, RegexEntityExtractor>() {
              @Override
              public RegexEntityExtractor call(ServiceResponse<RegexEntityExtractor> response) {
                  return response.body();
              }
          });
      }
docs: Gets information of a regex entity model.
  
  @param appId The application ID.
  @param versionId The version ID.
  @param regexEntityId The regex entity model ID.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the RegexEntityExtractor object