code: def tick_values(self, vmin, vmax):
      import bisect
  
      dtnums = super(RRuleLocator, self).tick_values(vmin, vmax)
      return [bisect.bisect_left(self._dates, x) for x in dtnums]
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import datetime
  import warnings
  from matplotlib.dates import AutoDateLocator
  from matplotlib.dates import RRuleLocator
  from matplotlib.dates import AutoDateFormatter
  from matplotlib.dates import HOURS_PER_DAY, MIN_PER_HOUR, SEC_PER_MIN, MONTHS_PER_YEAR, DAYS_PER_WEEK, SEC_PER_HOUR, SEC_PER_DAY, num2date, rrulewrapper, YearLocator, MicrosecondLocator
  from dateutil.relativedelta import relativedelta
  import numpy
label_desc: Use image node_id 4 for calling the RRuleLocator obj's underlying member method code with example usage: obj.tick_values(vmin, vmax) and returns: unknown