class _MISSING_TYPE:
    pass
MISSING = _MISSING_TYPE()

def field(*, default=MISSING, default_factory=MISSING, init=True, repr=True,
          hash=None, compare=True, metadata=None):
    pass
class _MISSING_TYPE:
    pass
MISSING = _MISSING_TYPE()

def field(*, default=MISSING, default_factory=MISSING, init=True, repr=True,
          hash=None, compare=True, metadata=None):
    pass