'Make sure that no sibling tree bbox\'s overlap.'

def _makeroom(self, treeseg):

    parent = treeseg.parent()
    if (not isinstance(parent, TreeSegmentWidget)):
        return
    index = parent.subtrees().index(treeseg)
    rsiblings = parent.subtrees()[(index + 1):]
    if rsiblings:
        dx = ((treeseg.bbox()[2] - rsiblings[0].bbox()[0]) + 10)
        for sibling in rsiblings:
            sibling.move(dx, 0)
    if (index > 0):
        lsibling = parent.subtrees()[(index - 1)]
        dx = max(0, ((lsibling.bbox()[2] - treeseg.bbox()[0]) + 10))
        treeseg.move(dx, 0)
    self._makeroom(parent)
