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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 trunc_normal_(x:Tensor, mean:float=0., std:float=1.) -> Tensor:
    "Truncated normal initialization."
    # From https://discuss.pytorch.org/t/implementing-truncated-normal-initializer/4778/12
    return x.normal_().fmod_(2).mul_(std).add_(mean)