public static Expression power(Expression expression1, Expression expression2) {
        return x("POWER(" + expression1.toString() + ", " + expression2.toString() + ")");
    }
public static Expression power ( Expression expression1 , Expression expression2 ) { return x ( "POWER(" + expression1 . toString ( ) + ", " + expression2 . toString ( ) + ")" ) ; }
Returned expression results in expression1 to the power of expression2.