docs: public static CmsXmlContentDefinition unmarshal(byte[] xmlData, String schemaLocation, EntityResolver resolver)
      throws CmsXmlException {
  
          schemaLocation = translateSchema(schemaLocation);
          CmsXmlContentDefinition result = getCachedContentDefinition(schemaLocation, resolver);
          if (result == null) {
              // content definition was not found in the cache, unmarshal the XML document
              result = unmarshalInternal(CmsXmlUtils.unmarshalHelper(xmlData, resolver), schemaLocation, resolver);
          }
          return result;
      }