code: def plot_pie(self, key="wall_time", minfract=0.05, **kwargs):
          
          timers = self.timers()
          n = len(timers)
  
          # Make square figures and axes
          import matplotlib.pyplot as plt
          from matplotlib.gridspec import GridSpec
          fig = plt.gcf()
          gspec = GridSpec(n, 1)
          for idx, timer in enumerate(timers):
              ax = plt.subplot(gspec[idx, 0])
              ax.set_title(str(timer))
              timer.pie(ax=ax, key=key, minfract=minfract, show=False)
  
          return fig
docs: Plot pie charts of the different timers.
  
          Args:
              key: Keyword used to extract data from timers.
              minfract: Don't show sections whose relative weight is less that minfract.
  
          Returns:
              `matplotlib` figure