/**
* @param callable $fn($key, $value)
* @return static
*/
public function filterKeys($fn)
{
return static::make(IterationTraits::filterKeys($this, $fn));
}
/**
* @param callable $fn($key, $value)
* @return static
*/
public function filterKeys($fn)
{
return static::make(IterationTraits::filterKeys($this, $fn));
}
