'Convert forward declaration to a dictionary.
A returned dictionary will be dumped to JSON while rendering widget.'

@staticmethod
def _make_forward_dict(f):

    if isinstance(f, six.string_types):
        return forward.Field(f).to_dict()
    elif isinstance(f, forward.Forward):
        return f.to_dict()
    else:
        raise TypeError('Cannot    use    {}    as    forwarded    value'.format(f))
