Getting error 1144: Interface method readExternal in namespace flash.utils:IExternalizable is implemented with an incompatible signature
public class Data extends EventDispatcher implements IExternalizable public function writeExternal(output:IDataOutput) { output.writeObject(_nodes); output.writeObject(_edges); output.writeObject(_span); output.writeObject(_groups); output.writeObject(_root); output.writeObject(_tree); } public function readExternal(input:IDataInput) { _nodes = input.readObject(); _edges = input.readObject(); _span = input.readObject(); _groups = input.readObject(); _root = input.readObject(); _tree = input.readObject(); }