def is_symmetric(sp):
    """ A SkewPartition is *symmetric* if its inner and outer shapes are symmetric.

    Return ``True`` if and only if the :class:`SkewPartition` ``sp`` is equal to its own conjugate.

    EXAMPLES::

        sage: SkewPartition([[], []]).is_symmetric()
        sage: True
        sage: SkewPartition([[1], []]).is_symmetric()
        sage: True
        sage: SkewPartition([[4, 3, 3, 1], [1]]).is_symmetric()
        sage: True
        sage: SkewPartition([[4, 3, 3, 1], [1, 1]]).is_symmetric()
        sage: False
        sage: SkewPartition([[5, 3, 3, 1], [2, 2]]).is_symmetric()
        sage: False

    ..  SEEALSO::

        :meth:`Partition.is_symmetric`
    """
    return sp == sp.conjugate()
