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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 get_model_field(schema, field):
 """Get the model field of a schema field :param Schema schema: a marshmallow schema :param str field: the name of the schema field :return str: the name of the field in the model """

    if schema._declared_fields.get(field) is None:
        raise Exception("{} has no attribute {}".format(schema.__name__, field))

    if schema._declared_fields[field].attribute is not None:
        return schema._declared_fields[field].attribute
    return field