public static ValueUpdate createDivide(FieldValue key, Number divisor) {
        return createMap(key, createDivide(divisor));
    }
Creates a new value update that divides a weight in a weighted set. Note that this method is just a convenience
method, it simply creates a divide value update by calling createDivide() and then creates a map value
update by calling createMap() with the key and the divide value update as parameters.

@param key the key whose weight in the weighted set to divide
@param divisor the number to divide by
@return a ValueUpdate specifying the division
@see ValueUpdate#createDivide(Number)
@see ValueUpdate#createMap(FieldValue, ValueUpdate)
document/src/main/java/com/yahoo/document/update/ValueUpdate.java