Bug 176450 Support link to CSS Feature(Model Part)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/PropertyCommand.java
*            the new name
	 * @return <code>true</code> if the name is valid. Otherwise
	 *         <code>false</code>.
	 */
	private boolean isGroupNameValidInContext( String groupName )
	{
		assert element instanceof GroupElement;
		if ( groupName == null )
			return true;
		if ( element.getContainer( ) != null )
		{
			DesignElement tmpContainer = element.getContainer( );
			List errors = GroupNameValidator.getInstance( )
					.validateForRenamingGroup(
							(ListingHandle) tmpContainer.getHandle( module ),
							(GroupHandle) element.getHandle( module ),
							groupName );
			if ( !errors.isEmpty( ) )
				return false;
		}
		return true;
	}
	/**
	 * Clears the value of a property.
	 * 
	 * @param propName
	 *            the name of the property to clear.
	 * @throws SemanticException
	 *             if failed to clear property.
	 */