Bug 152430 Key can modify to empty string
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/command/PropertyCommand.java
}
		stack.commit( );
	}
	/**
	 * Validates the values of the item members.
	 * 
	 * @param ref
	 *            reference to a list.
	 * @param item
	 *            the item to check
	 * @throws SemanticException
	 *             if the item has any member with invalid value or if the given
	 *             structure is not of a valid type that can be contained in the
	 *             list.
	 */
	private void checkItemName( MemberRef memberRef, String newName )
			throws SemanticException
	{
		PropertyDefn propDefn = memberRef.getPropDefn( );
		Structure structure = memberRef.getStructure( module, element );
		List errors = StructureListValidator.getInstance( )
				.validateForRenaming( element.getHandle( module ), propDefn,
						memberRef.getList( module, element ), structure,
						memberRef.getMemberDefn( ), newName );
		if ( errors.size( ) > 0 )
		{
			throw (PropertyValueException) errors.get( 0 );
		}
	}
}