class_docstr: Support for `Visual Chart <www.visualchart.com>`_ binary on-disk files for
  both daily and intradaily formats.
  
  Note:
  
    - ``dataname``: Market code displayed by Visual Chart. Example: 015ES for
      EuroStoxx 50 continuous future
code: def _load(self):
      if self.f is None:
          return False  # cannot load more
  
      try:
          bardata = self.f.read(self._barsize)
      except IOError:
          self.f = None  # cannot return, nullify file
          return False  # cannot load more
  
      if not bardata or len(bardata) < self._barsize:
          self.f = None  # cannot return, nullify file
          return False  # cannot load more
  
      try:
          bdata = unpack(self._barfmt, bardata)
      except:
          self.f = None
          return False
  
      # First Date
      y, md = divmod(
          bdata[0], 500
      )  # Years stored as if they had 500 days
      m, d = divmod(md, 32)  # Months stored as if they had 32 days
      dt = datetime(y, m, d)
  
      # Time
      if self._dtsize > 1:  # Minute Bars
          # Daily Time is stored in seconds
          hhmm, ss = divmod(bdata[1], 60)
          hh, mm = divmod(hhmm, 60)
          dt = dt.replace(hour=hh, minute=mm, second=ss)
      else:  # Daily Bars
          dt = datetime.combine(dt, self.p.sessionend)
  
      self.lines.datetime[0] = date2num(dt)  # Store time
  
      # Get the rest of the fields
      o, h, l, c, v, oi = bdata[self._dtsize :]
      self.lines.open[0] = o
      self.lines.high[0] = h
      self.lines.low[0] = l
      self.lines.close[0] = c
      self.lines.volume[0] = v
      self.lines.openinterest[0] = oi
  
      return True
  
file_path: backtrader/backtrader/feeds/vchartfile.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  from datetime import datetime
  from struct import unpack
  import os.path
  import backtrader
  from backtrader import date2num
label_desc: Use image node_id 3 for calling the VChartFile obj's underlying member method code with example usage: obj._load() and returns: True, False, False, False, False