Bug 118592 Report error
please see attached design file.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/ResultIterator.java
this.getRdSaveUtil( ).doSaveExpr( dataExpr, exprValue );
		
		return exprValue;
	}
	
	/**
	 * @return
	 */
	private RDSaveUtil getRdSaveUtil( )
	{
		if ( this.rdSaveUtil == null )
		{
			rdSaveUtil = new RDSaveUtil( this.context,
					this.queryResults.getID( ),
					this.odiResult );
		}
		
		return this.rdSaveUtil;
	}
	
	/**
	 * Returns the value of a query result expression as a Boolean, by type
	 * casting the Object returned by getValue. <br>
	 * A convenience method for the API consumer. <br>
	 * If the expression value has an incompatible type, a ClassCastException is
	 * thrown at runtime.
	 * 
	 * @param dataExpr
	 *            An IBaseExpression object provided in the ReportQueryDefn at
	 *            the time of prepare.