Function mapToArray

mapToArray<K, V, R>(
m: ReadonlyMap<K, V>,
transformer: (key: K, item: V) => R,
): readonly R[]
Converts Map to Array with a provided transformer function. Useful for plucking out certain properties from contained values and for creating a new map based on transformed values from an input map.
Type Parameters
- K
- V
- R
Parameters
- m: ReadonlyMap<K, V>
- transformer: (key: K, item: V) => R
  A function that takes a key and item, returning a new item.
Returns readonly R[]
Example: Get an array of ages from a map of Person objects
```
let person = { age: 29, name: `John`};
map.add(person.name, person);

const ages = mapToArray(map, (key, person) => person.age);
// [29, ...]
```
In the above example, the transformer function returns a number, but it could just as well return a transformed version of the input:
```
// Return with random heights and uppercased name
mapToArray(map, (key, person) => ({
 ...person,
 height: Math.random(),
 name: person.name.toUpperCase();
}))
// Yields:
// [{height: 0.12, age: 29, name: "JOHN"}, ...]
```