docs: private String getPropertyName(Expression expression) {
  		if (!(expression instanceof PropertyName)) {
  			throw new IllegalArgumentException("Expression " + expression + " is not a PropertyName.");
  		}
  		String name = ((PropertyName) expression).getPropertyName();
  		if (name.endsWith(FilterService.ATTRIBUTE_ID)) {
  			// replace by Hibernate id property, always refers to the id, even if named differently
  			name = name.substring(0, name.length() - FilterService.ATTRIBUTE_ID.length()) + HIBERNATE_ID;
  		}
  		return name;
  	}