def _merge_dictionaries(x, y):
    """Merge `dicts` together

    Create a copy of `x`, and update that with elements of `y`, to prevent
    squashing of passed in dicts.

    :param dict x: Dictionary 1
    :param dict y: Dictionary 2
    :returns: Merged dictionary
    :rtype: `dict`
    """

    z = x.copy()
    z.update(y)
    return z