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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_consonant(sign):
 """ Uses dictionary to replace ATF convention for unicode characters. input = ['as,', 'S,ATU', 'tet,', 'T,et', 'sza', 'ASZ'] output = ['aṣ', 'ṢATU', 'teṭ', 'Ṭet', 'ša', 'AŠ'] :param sign: string :return: string """

        for key in TITTLES:
            sign = sign.replace(key, TITTLES[key])
        return sign