This function enumerates all possible binary trees with n unlabeled leaves. Each tree is an object of class LeafTree. Each class of unlabeled tree is represented by a particular labeling of that tree. Some duplicates may appear in the list, but each equivalence class is guaranteed to appear at least once.

For n larger than 5, some equivalence classes of trees may appear more than once.
The object unlabeledTrees is a method function.