Function groupBy

groupBy(
    collection: unknown[],
    keyFunc: Callback<unknown>,
    hashFunc?: HashFunction,
): Map<unknown, unknown[]>
Groups the collection into sets by the returned key
Parameters
- collection: unknown[]
- keyFunc: Callback<unknown>
  {Function} to compute the group key of an item in the collection
- hashFunc: HashFunction = DEFAULT_HASH_FUNCTION
Returns Map<unknown, unknown[]>
- Defined in src/util.ts:483