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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 iter_params_for_processing(invocation_order, declaration_order):
 """Given a sequence of parameters in the order as should be considered for processing and an iterable of parameters that exist, this returns a list in the correct order as they should be processed. """

    def sort_key(item):
        try:
            idx = invocation_order.index(item)
        except ValueError:
            idx = float('inf')
        return (not item.is_eager, idx)

    return sorted(declaration_order, key=sort_key)