This removes the object from its old parent, and attaches it to the new object. Adds the given object as a child. Removes the given object from the list of children. Determines if the given object is an ancestor of this object. Does NOT check recursively.
Returns null if no such child exists.
Does NOT check recursively. Make a specifier, starting at the root and write it to the output object. Adds the identifier for this object to the end of the Specifier. Sets the default root, which is the parent when no other is specified. Return the Specifiable described by the specifier in relation to myself.