doCompare method Null safety
- covariant FocusOrder other
The subclass implementation called by compareTo to compare orders.
The argument is guaranteed to be of the same runtimeType as this object.
The method should return a negative number if this object comes earlier in
the sort order than the
other argument; and a positive number if it
comes later in the sort order than
other. Returning zero causes the
system to fall back to the secondary sort order defined by
@protected int doCompare(covariant FocusOrder other);