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

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