return null;
	private String variableDeclarationStatementSelected(VariableDeclarationStatement vds) {		if (vds.fragments().size() != 1) {			return RefactoringCoreMessages.getString("ChangeTypeRefactoring.multiDeclarationsNotSupported"); //$NON-NLS-1$		} else {			ASTNode elem= (ASTNode) vds.fragments().iterator().next();			if (elem.getNodeType() == ASTNode.VARIABLE_DECLARATION_FRAGMENT) {				simpleNameSelected(((VariableDeclarationFragment) elem).getName());				fEffectiveSelectionStart= ((VariableDeclarationFragment) elem).getName().getStartPosition(); 				fEffectiveSelectionLength= ((VariableDeclarationFragment) elem).getName().getLength();			} else{				return nodeTypeNotSupported();			}		}		return null;	}