              xrng = list(range(self.calcs.iterations))
  
          keys = list(self.calcs.stats.keys())
  
          for idx, item in enumerate(self.lines_sort(keys)):
              if initiate:
                  self.lines.extend(self.ax1.plot(xrng, self.calcs.stats[item[0]],
                                                  label=item[1], linewidth=item[2], color=item[3]))
              else:
                  self.lines[idx].set_data(xrng, self.calcs.stats[item[0]])
 
</s> remove                 self.lines.extend(self.ax1.plot(xrng, self.calcs.stats[item[0]],
                                                label=item[1], linewidth=item[2], color=item[3]))
 </s> add                 self._lines.extend(self._ax1.plot(xrng, self._calcs.stats[item[0]],
                                                  label=item[1], linewidth=item[2], color=item[3])) </s> remove         keys = list(self.calcs.stats.keys())
 </s> add         keys = list(self._calcs.stats.keys()) </s> remove                 self.lines[idx].set_data(xrng, self.calcs.stats[item[0]])
 </s> add                 self._lines[idx].set_data(xrng, self._calcs.stats[item[0]]) </s> remove             xrng = list(range(self.calcs.iterations))
 </s> add             xrng = list(range(self._calcs.iterations)) </s> remove         if self.calcs.start_iteration > 0:
            end_iteration = self.calcs.start_iteration + self.calcs.iterations
            xrng = list(range(self.calcs.start_iteration, end_iteration))
 </s> add         if self._calcs.start_iteration > 0:
            end_iteration = self._calcs.start_iteration + self._calcs.iterations
            xrng = list(range(self._calcs.start_iteration, end_iteration))
        for idx, item in enumerate(self._lines_sort(keys)):
              xrng = list(range(self.calcs.iterations))
  
          keys = list(self.calcs.stats.keys())
  
        for idx, item in enumerate(self._lines_sort(keys)):
              if initiate:
                  self.lines.extend(self.ax1.plot(xrng, self.calcs.stats[item[0]],
                                                  label=item[1], linewidth=item[2], color=item[3]))
              else:
                  self.lines[idx].set_data(xrng, self.calcs.stats[item[0]])
keep keep keep keep replace keep keep keep keep keep
 Update matplotlib requirement
  - bump min requirement to 3.5.1
  - Fix custom toolbar for v3.5.1
  - Documentation + linting 
lib/gui/display_graph.py