DeepCollectionEquality.unordered constructor

const DeepCollectionEquality.unordered([Equality base = const DefaultEquality() ])

Creates a deep equality on collections where the order of lists and iterables are not considered important. That is, lists and iterables are treated as unordered iterables.

Implementation 

const DeepCollectionEquality.unordered(
    [Equality base = const DefaultEquality()])
    : _base = base,
      _unordered = true;