Map after an operation has been applied to each value in the
public function map<Tu>(
): Map<Tk, Tu>;
Every value in the current
Map is affected by a call to
filter() where only values that meet a certain criteria are affected.
The keys will remain unchanged from the current
Map to the returned
(function(Tv):Tu) $callback - The callback containing the operation to apply to the
Map<Tk, Tu> - a
Map containing key/value pairs after a user-specified
operation is applied.