def METHOD_NAME(self, index):
    """
    Retrieves the presence status of power supply unit (PSU) defined
            by index <index>
    :param index: An integer, index of the PSU of which to query status
    :return: Boolean, True if PSU is plugged, False if not
    """
    status = 0
    psu_presence = self.get_cpld_register('psu'+self._psu_mapping[index]+'_prs')
    if (psu_presence != 'ERR'):
        status = int(psu_presence, 10)
    return status