/// isEqual - Returns true if two lists are equal. Because all lists created
/// from the same ImmutableListFactory are uniqued, this has O(1) complexity
/// because it the contents of the list do not need to be compared. Note
/// isEqual - Returns true if two lists are equal. Because all lists created
/// from the same ImmutableListFactory are uniqued, this has O(1) complexity
/// because it the contents of the list do not need to be compared. Note