'Parse a human readable string of a duration.
Args:
timestring: The string to parse.'

def ParseFromHumanReadable(self, timestring):

    if (not timestring):
        return
    orig_string = timestring
    multiplicator = 1
    if timestring[(-1)].isdigit():
        pass
    else:
        try:
            multiplicator = self.DIVIDERS[timestring[(-1)]]
        except KeyError:
            raise RuntimeError(("Invalid    duration    multiplicator:    '%s'    ('%s')." % (timestring[(-1)], orig_string)))
        timestring = timestring[:(-1)]
    try:
        self._value = (int(timestring) * multiplicator)
    except ValueError:
        raise InitializeError(("Could    not    parse    expiration    time    '%s'." % orig_string))
