numeric func
A function to "reset" tree_window. This removes all treenodes from the window and is equivalent to calling treenode.kill on every one.
A value of 0 is returned when successful, and a value of 1 is returned on error.
The code of the function cannot be redefined.
window.reset (<window>)
The function may be called in one of two ways:
# Assume mywin is the tree window identifier window.reset(mywin)or
mywin.reset()