code: public DataTransformator mediaType(MediaType mediaType) {
  		checkNotNull(mediaType,MEDIA_TYPE_CANNOT_BE_NULL);
  		DataTransformator result = new DataTransformator(this);
  		result.setMediaType(mediaType);
  		return result;
  	}
docs: Create transformator with the specified media type
  
  @param mediaType
  the new media type
  @return a new transformator with the same configuration except for the
  media type, which is set to the specified one
  @throws UnsupportedMediaTypeException
  if the media type is not valid