Map.keysForValue
keysForValue($value) -> list
Description
Return a list of Map keys that are assigned to the given value.
$map = { a: 123, b: 123, z: 999 }
$map.keysForValue(123)
//= ['a', 'b']
$map.keysForValue(999)
//= ['z']
$map.keysForValue('X')
//= []