code: @Override
  	protected void validateContents(Contents contents) {
  		// Verify the Contents have a relation name data type
  		String contentsDataType = contents.getDataTypeString();
  		if (contentsDataType == null || !contentsDataType.equals(dataType)) {
  			throw new GeoPackageException("The "
  					+ Contents.class.getSimpleName() + " of a "
  					+ getClass().getSimpleName() + " must have a data type of "
  					+ dataType);
  		}
  	}
docs: {@inheritDoc}