Function mutable

mutable<K, V>(...data: EitherKey<K, V>): IMapMutable<K, V>
Returns a IMapMutable (which just wraps the in-built Map) Use Maps.immutable for the immutable alternative.
Type Parameters
- K
- V
Parameters
- ...data: EitherKey<K, V>
  Optional initial data in the form of an array of { key: value } or [ key, value ]
Returns IMapMutable<K, V>
Example: Basic usage
```
const m = mapMutable();
// Add one or more entries
m.add(["name", "sally"]);
// Alternatively:
m.set("name", "sally");
// Recall
m.get("name");           // "sally"
m.delete("name");
m.isEmpty; // True
m.clear();
```