code: public CMAContentType publish(CMAContentType contentType) {
      assertNotNull(contentType, "contentType");
  
      final String contentTypeId = getResourceIdOrThrow(contentType, "contentType");
      final String spaceId = getSpaceIdOrThrow(contentType, "contentType");
      final String environmentId = contentType.getEnvironmentId();
  
      return service.publish(
          contentType.getVersion(),
          spaceId,
          environmentId,
          contentTypeId
      ).blockingFirst();
    }
docs: Publish a Content Type.
  
  @param contentType Content Type
  @return {@link CMAContentType} result instance
  @throws IllegalArgumentException if contentType is null.
  @throws IllegalArgumentException if contentType's id is null.
  @throws IllegalArgumentException if contentType's space id is null.