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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def to_fp16(learn:Learner, loss_scale:float=None, max_noskip:int=1000, dynamic:bool=True, clip:float=None,
            flat_master:bool=False, max_scale:float=2**24)->Learner:
    "Put `learn` in FP16 precision mode."
    learn.to_fp32()
    learn.model = model2half(learn.model)
    learn.data.add_tfm(batch_to_half)
    learn.mp_cb = MixedPrecision(learn, loss_scale=loss_scale, max_noskip=max_noskip, dynamic=dynamic, clip=clip, 
                                 flat_master=flat_master, max_scale=max_scale)
    learn.callbacks.append(learn.mp_cb)
    return learn