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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 convert_sbcs_model(old_model, alphabet):
 """Create a SingleByteCharSetModel object representing the charset."""

    # Setup tables necessary for computing transition frequencies for model
    char_to_order = {i: order
                     for i, order in enumerate(old_model['char_to_order_map'])}
    pos_ratio = old_model['typical_positive_ratio']
    keep_ascii_letters = old_model['keep_english_letter']

    curr_model = SingleByteCharSetModel(charset_name=old_model['charset_name'],
                                        language=old_model['language'],
                                        char_to_order_map=char_to_order,
                                        # language_model is filled in later
                                        language_model=None,
                                        typical_positive_ratio=pos_ratio,
                                        keep_ascii_letters=keep_ascii_letters,
                                        alphabet=alphabet)
    return curr_model