docs: protected String getFileEncoding(CmsObject cms, String filename) {
  
          try {
              return cms.readPropertyObject(filename, CmsPropertyDefinition.PROPERTY_CONTENT_ENCODING, true).getValue(
                  OpenCms.getSystemInfo().getDefaultEncoding());
          } catch (CmsException e) {
              return OpenCms.getSystemInfo().getDefaultEncoding();
          }
      }