def clear(self):
if self._child is not None:<EOL><INDENT>self._detach_child(self._child)<EOL><DEDENT>self._child = None<EOL>assert len(self) == <NUM_LIT:0><EOL>self._repack_and_regroup_children()<EOL>
Empty the bin.

It's OK to call this method if the bin is empty to begin with.