code: def plot_series(filename, plot_kwargs=None):
      """Plot series data from MonitorSeries output text file.
  
      Args:
          filename (str): Path to *.series.txt file produced by :obj:`~nnabla.MonitorSeries` class.
          plot_kwags (dict, optional):
              Keyward arguments passed to :function:`matplotlib.pyplot.plot`.
  
      Note:
          matplotlib package is required.
  
      """
      import matplotlib.pyplot as plt
  
      if plot_kwargs is None:
          plot_kwargs = {}
  
      data = np.genfromtxt(filename, dtype="i8,f4", names=["k", "v"])
      index = data["k"]
      values = data["v"]
      plt.plot(index, values, **plot_kwargs)
  
imports: from __future__ import print_function
  import numpy
  import os
  import time
  from nnabla.logger import logger
label_desc: Use image node_id 2 for calling a global function with example usage: plot_series(filename, plot_kwargs) without return types