Bug 201030 NPE throws out when preview the attached report design
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/script/ScriptEvalUtil.java
*/
		private static boolean isNumericOrString( Object result )
		{
			return ( result instanceof Number ) || ( result instanceof String );
		}
		/**
		 * 
		 * @param result
		 * @return
		 */
		private static boolean isDateOrString( Object result )
		{
			return ( result instanceof Date ) || ( result instanceof String );
		}
		
		/**
		 * 
		 * @param result
		 * @return
		 */
		private static boolean isBooleanOrString( Object result )
		{
			return ( result instanceof Boolean ) || ( result instanceof String );
		}
		
		/**
		 * 
		 * @param obj
		 * @param operator
		 * @param operands