'Mark every minute in *byminute*; *byminute* can be an int or
sequence.  Default is to tick every minute: ``byminute=range(60)``
*interval* is the interval between each iteration.  For
example, if ``interval=2``, mark every second occurrence.'

def __init__(self, byminute=None, interval=1, tz=None):

    if (byminute is None):
        byminute = range(60)
    rule = rrulewrapper(MINUTELY, byminute=byminute, interval=interval, bysecond=0)
    RRuleLocator.__init__(self, rule, tz)
