def requires_grad(m:nn.Module, b:Optional[bool]=None)->Optional[bool]:
    "If `b` is not set return `requires_grad` of first param, else set `requires_grad` on all params as `b`"
    ps = list(m.parameters())
    if not ps: return None
    if b is None: return ps[0].requires_grad
    for p in ps: p.requires_grad=b
def requires_grad ( m : nn . Module , b : Optional [ bool ] = None ) -> Optional [ bool ] : ps = list ( m . parameters ( ) ) if not ps : return None if b is None : return ps [ 0 ] . requires_grad for p in ps : p . requires_grad = b
If `b` is not set return `requires_grad` of first param, else set `requires_grad` on all params as `b`