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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 _yield_estimators(model):
 """Yield estimator and its prefix from the model. First, pipeline preprocessing steps are yielded (if there are any). Next the neural net is yielded. Finally, the module is yielded. """

    yield from _yield_preproc_steps(model)

    net_prefixes = []
    module_prefixes = []

    if isinstance(model, Pipeline):
        name = model.steps[-1][0]
        net_prefixes.append(name)
        module_prefixes.append(name)
        net = model.steps[-1][1]
    else:
        net = model

    yield '__'.join(net_prefixes), net

    module = net.module
    module_prefixes.append('module')
    yield '__'.join(module_prefixes), module