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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 quote_identifier(identifier: str, mixed: Union[SQLCompiler, Engine, Dialect]) -> str: """ Converts an SQL identifier to a quoted version, via the SQL dialect in use. Args: identifier: the identifier to be quoted mixed: an SQLAlchemy :class:`SQLCompiler`, :class:`Engine`, or :class:`Dialect` object Returns: the quoted identifier """

    # See also http://sqlalchemy-utils.readthedocs.io/en/latest/_modules/sqlalchemy_utils/functions/orm.html  # noqa
    return get_preparer(mixed).quote(identifier)