attach method Null safety
- covariant Object owner
mustCallSuper">@mustCallSuper
Mark this node as attached to the given owner.
Typically called only from the parent's attach method, and by the
owner
to mark the root of a tree as attached.
Subclasses with children should override this method to first call their
inherited attach method, and then attach all their children to the
same owner
.
Implementations of this method should start with a call to the inherited
method, as in super.attach(owner)
.
Implementation
@mustCallSuper
void attach(covariant Object owner) {
assert(owner != null);
assert(_owner == null);
_owner = owner;
}