docs: def _coord(self):
          """Attribute indicating the tree coordinates for this node.
  
          The tree coordinates of a node are expressed as a tuple of the
          indices of the node and its ancestors, for example:
          A grandchild node with node path 
          `/root.name/root.childs[2].name/root.childs[2].childs[0].name` 
          would have coordinates `(2,0)`.
          The root node _coord is an empty tuple: `()`
  
          :returns: the tree coordinates for this node.
          :rtype: tuple 
          """
          _coord = []
          _node = self
          while _node.parent:
              _idx = _node.parent.childs.index(_node)
              _coord.insert(0, _idx)
              _node = _node.parent
          return tuple(_coord)