docs: @Override
      public AttachmentResourceWritable addContent(File file, String name) throws RepositoryException {
          if (_contentAttached) {
              throw new RepositoryResourceValidationException("addContent(" + file.getAbsolutePath()
                                                              + ") called for resource " + getName() + " which all ready has a CONTENT attachment", getId());
          }
          _contentAttached = true;
          AttachmentResourceWritable at = addAttachment(file, AttachmentType.CONTENT, name);
          setMainAttachmentSize(at.getSize());
          try {
              setMainAttachmentSHA256((file == null) ? null : HashUtils.getFileSHA256String(file));
          } catch (IOException ioe) {
              throw new RepositoryException(ioe);
          }
          return at;
      }