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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 parse_sas_token(sas_token):
 """Parse a SAS token into its components. :param sas_token: The SAS token. :type sas_token: str :rtype: dict[str, str] """

    sas_data = {}
    token = sas_token.partition(' ')[2]
    fields = token.split('&')
    for field in fields:
        key, value = field.split('=', 1)
        sas_data[key.lower()] = value
    return sas_data