docs: def save_image_to_disk(self, filename_1 = None, filename_2 = None):
          """
          creates an image using the scripts plot function and writes it to the disk
          for single plots (plot_type: 'main', 'aux')
              - if no filname provided take default name
          for double plots (plot_type: 'main', 'aux')
              - if no filnames provided take default name
              - if only one filname provided save only the plot for which name is provided
          Args:
              filename_1: filname for figure 1
              filename_2: filname for figure 1
  
          Returns: None
  
          """
  
          def axes_empty(ax):
              """
              takes an axes object and checks if it is empty
              the axes object is considered empty it doesn't contain any of the following:
                  - lines
                  - images
                  - patches
              Returns:
  
              """
  
              is_empty = True
  
              if ax is not None and len(ax)>0:
                  for a in ax:
                      if len(a.lines)+len(a.images)+len(a.patches) != 0:
                          is_empty = False
  
  
              return is_empty
  
          # create and save images
          if (filename_1 is None):
              filename_1 = self.filename('-plt1.png')
  
          if (filename_2 is None):
              filename_2 = self.filename('-plt2.png')
  
  
          # windows can't deal with long filenames so we have to use the prefix '\\\\?\\'
          # if len(filename_1.split('\\\\?\\')) == 1:
          #     filename_1 = '\\\\?\\' + filename_1
          # if len(filename_2.split('\\\\?\\')) == 1:
          #     filename_2 = '\\\\?\\' + filename_2
  
          if os.path.exists(os.path.dirname(filename_1)) is False:
              os.makedirs(os.path.dirname(filename_1))
          if os.path.exists(os.path.dirname(filename_2)) is False:
              os.makedirs(os.path.dirname(filename_2))
  
  
          fig_1 = Figure()
          canvas_1 = FigureCanvas(fig_1)
  
          fig_2 = Figure()
          canvas_2 = FigureCanvas(fig_2)
  
          self.force_update()
  
          self.plot([fig_1, fig_2])
  
          if filename_1 is not None and not axes_empty(fig_1.axes):
              fig_1.savefig(filename_1)
          if filename_2 is not None and not axes_empty(fig_2.axes):
              fig_2.savefig(filename_2)