public static ValueUpdate createMultiply(Number factor) {
        return new ArithmeticValueUpdate(ArithmeticValueUpdate.Operator.MUL, factor);
    }
Creates a new value update that multiplies a value. Note that the data type must be a numeric
type.

@param factor the number to multiply by
@return a ValueUpdate specifying the multiplication
@throws UnsupportedOperationException if the data type is non-numeric
document/src/main/java/com/yahoo/document/update/ValueUpdate.java