def __init__(self, default_value=None, allow_none=True, **metadata):
        """Create a dict trait type from a dict.

        The default value is created by doing ``dict(default_value)``,
        which creates a copy of the ``default_value``.
        """
        if default_value is None:
            args = ((),)
        elif isinstance(default_value, dict):
            args = (default_value,)
        elif isinstance(default_value, SequenceTypes):
            args = (default_value,)
        else:
            raise TypeError(default_value % 'default value of Dict was %s')

        super(Dict,self).__init__(klass=dict, args=args,
                                  allow_none=allow_none, **metadata)
dataset/ETHPy150Open enthought/depsolver/depsolver/bundled/traitlets/_implementation.py/Dict.__init__/swapped operands of `%`