sunpy/sunpy — pull request #831 by derdon (2014-02-13 22:00:02+00:00)
Title: "fixed" MapCube.coalign

This *may* call the ``_coalign_diff`` method (if the passed argument is
``"diff"``) which raises NotImplementedError. Otherwise, ``None`` is
returned. Seems kinda not-finished-yet to me. At least MapCube.coalign won't raise a NameError anymore, yay.