Bug 136740 Error exporting data from a grouped report.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ExprManagerUtil.java
{
	/**
	 * 
	 */
	private List children;
	private String value;
	/**
	 * 
	 * @param value
	 */
	Node( String value )
	{
		this.value = value;
		this.children = new ArrayList( );
	}
	/**
	 * 
	 * @return
	 */
	public String getValue( )
	{