Bug 201019 [Automation][Regression]Exception is thrown when running reportdesign
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/adapter/ExpressionUtil.java
}
	/**
	 * Test whether the char immediately before the candidate "row" key is
	 * valid.
	 * 
	 * @param operator
	 * @return
	 */
	private static boolean isValidProceeding( char operator )
	{
		if ( ( operator >= 'A' && operator <= 'Z' )
				|| ( operator >= 'a' && operator <= 'z' ) || operator == '_' )
			return false;
		return true;
	}
	
	public IConditionalExpression createConditionalExpression(
			String testExpression, String operator, String value1, String value2 )
	{
		ConditionalExpression expression = new ConditionalExpression( testExpression,
				DataAdapterUtil.adaptModelFilterOperator( operator ),
				value1,
				value2 );
		return ExpressionUtil.transformConditionalExpression( expression );
	}
}
/**
 * 
 */
class TotalExprBinding implements ITotalExprBindings