dart List Filters
Introduction
Dart filters lists through the List.where and List.retainWhere methods. The where function takes one argument: a boolean function that is applied to each element of the list. If the function evaluates to true then the list element is retained; if the function evaluates to false, the element is removed.
Calling theList.retainWhere(foo) is practically equivalent to setting theList = theList.where(foo).
