if( dockable.getDockParent() == station.getStation() )
throw new IllegalStateException( "dockable already a child" );
DockableSplitDockTree tree = getStation().createTree();
if( tree.getRoot() == null )
tree.root( dockable );
else{
tree.root( tree.horizontal( tree.put( dockable ), tree.unroot() ) );
}
getStation().dropTree( tree, false );
}