superjson/pkg/dateutil/tz/_common.py
def _validate_fromutc_inputs(f):
    """
    The CPython version of ``fromutc`` checks that the input is a ``datetime``
    object and that ``self`` is attached as its ``tzinfo``.
    """
    @wraps(f)
    def fromutc(self, dt):
        if not isinstance(dt, datetime):
            raise TypeError("fromutc() requires a datetime argument")
        if dt.tzinfo is not self:
            raise ValueError("dt.tzinfo is not self")

        return f(self, dt)

    return fromutc
def _validate_fromutc_inputs(f):
    """
    The CPython version of ``fromutc`` checks that the input is a ``datetime``
    object and that ``self`` is attached as its ``tzinfo``.
    """
    @wraps(f)
    def fromutc(self, dt):
        if not isinstance(dt, datetime):
            raise TypeError("fromutc() requires a datetime argument")
        if dt.tzinfo is not self:
            raise ValueError("dt.tzinfo is not self")

        return f(self, dt)

    return fromutc
The CPython version of ``fromutc`` checks that the input is a ``datetime``
    object and that ``self`` is attached as its ``tzinfo``.