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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 _model_foreign(ins):
 """ Get foreign keys info :type ins: sqlalchemy.orm.mapper.Mapper :rtype: list[SaForeignkeyDoc] """

    fks = []
    for t in ins.tables:
        fks.extend([
            SaForeignkeyDoc(
                key=fk.column.key,
                target=fk.target_fullname,
                onupdate=fk.onupdate,
                ondelete=fk.ondelete
            )
            for fk in t.foreign_keys])
    return fks