For the following messages, map stands for an associative array or a reference to one.
Returns the first key within map, or Empty() if map has no keys. Note that keys are returned in lexicographical order.
Inserts the key into map and assigns value to it. If key already exists in map, its value is replaced by the new value given. This message is equivalent to the function Insert Into.
Returns the key following the given key within the map, or Empty() if map has no keys. Note that keys are returned in lexicographical order.
Removes the key and value from map. This message is equivalent to the function Remove From.

Help created on 7/12/2018