def METHOD_NAME(self):
    """Node z-coordinates.
    Examples
    --------
    >>> from landlab.grid.unstructured.nodes import NodeGrid
    >>> ngrid = NodeGrid(([0, 0, 1], [0, 1, 0]))
    >>> ngrid.y
    array([ 0.,  0.,  1.])
    """
    try:
        return self._coords[-2]
    except IndexError as exc:
        raise AttributeError("Grid has no z-coordinate") from exc