Performs an *in-place* deep-merge of key-values from :attr:`incoming`
    into :attr:`base`.  No attempt is made to preserve the original state of
    the objects passed in as arguments.

    :param dict base:  The target container for the merged values.  This will
        be modified *in-place*.
    :type base:  Any :class:`dict`-like object

    :param dict incoming:  The container from which incoming values will be
        copied.  Nested dicts in this will be modified.
    :type incoming:  Any :class:`dict`-like object

    :rtype:  None

def deep_merge_dicts(base, incoming):
    """
    Performs an *in-place* deep-merge of key-values from :attr:`incoming`
    into :attr:`base`.  No attempt is made to preserve the original state of
    the objects passed in as arguments.

    :param dict base:  The target container for the merged values.  This will
        be modified *in-place*.
    :type base:  Any :class:`dict`-like object

    :param dict incoming:  The container from which incoming values will be
        copied.  Nested dicts in this will be modified.
    :type incoming:  Any :class:`dict`-like object

    :rtype:  None

    """
    for ki, vi in incoming.iteritems():
        if (ki in base
                and isinstance(vi, collections.MutableMapping)
                and isinstance(base[ki], collections.MutableMapping)
                ):
            deep_merge_dicts(base[ki], vi)
        else:
            base[ki] = vi