public static ValueUpdate createIncrement(Number increment) {
        return new ArithmeticValueUpdate(ArithmeticValueUpdate.Operator.ADD, increment);
    }
Creates a new value update that increments a value. Note that the data type must be a numeric
type.

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