code: def next(self):
      self._daycount()
  
      tm = self.data.datetime.time()
      if not self._barisvalid(tm):
          return
  
      # Record the "minute/second" of this day has been seen
      self.vcount[tm] += 1
  
      # Get the bar's volume
      vol = self.data.volume[0]
  
      # If number of days is right, we saw the same "minute/second" last day
      if self.vcount[tm] == self.days:
          self.lines.rvbb[0] = vol / self.pvol[tm]
  
      # Synchronize the days and volume count for next cycle
      self.vcount[tm] = self.days
  
      # Record the volume for this bar for next cycle
      self.pvol[tm] = vol
  
file_path: backtrader/samples/relative-volume/relvolbybar.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import collections
  import datetime
  import math
  import backtrader
label_desc: Use image node_id 6 for calling the RelativeVolumeByBar obj's underlying member method code with example usage: obj.next() without return types