docstr: Return the label for time x at position pos
docstr_tok: ["Return","the","label","for","time","x","at","position","pos"]
code: def __call__(self, x, pos=0):
      """Return the label for time x at position pos"""
      ind = int(round(x))
      if ind >= self.lendates:
          ind = self.lendates - 1
  
      if ind < 0:
          ind = 0
  
      return num2date(self.dates[ind]).strftime(self.fmt)
  
file_path: backtrader/backtrader/plot/formatters.py
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import matplotlib.dates
  import matplotlib.ticker
  from ..utils import num2date
label_desc: Use image node_id 2 for calling the MyDateFormatter obj's underlying member method code with example usage: obj.__call__(x, pos) and returns: num2date