| Iterator |
| CollectionTrait | Offers a handful of method to manipulate iterators |
| ExtractTrait | Provides utility protected methods for extracting a property or column from an array or object. |
| CollectionInterface | Describes the methods a Collection should implement. A collection is an immutable list of elements exposing a number of traversing and extracting method for generating other collections. |
| Collection | A collection is an immutable list of elements with a handful of functions to iterate, group, transform and extract information from it. |
