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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 bn2float(module:nn.Module)->nn.Module:
    "If `module` is batchnorm don't use half precision."
    if isinstance(module, torch.nn.modules.batchnorm._BatchNorm): module.float()
    for child in module.children(): bn2float(child)
    return module