Bug 136740 Error exporting data from a grouped report.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ExprManagerUtil.java
return this.value;
	}
	/**
	 * 
	 * @param n
	 */
	public void addChild( Node n )
	{
		this.children.add( n );
	}
	/**
	 * 
	 * @return
	 */
	public List getChildren( )
	{
		return this.children;
	}
	/*
	 * (non-Javadoc)
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	public boolean equals( Object o )
	{
		if ( ( o instanceof Node ) && ( (Node) o ).value.equals( this.value ) )
			return true;
		return false;
	}
}