code: def is_ready_to_next_step(self):
          
          # Still editing
          if self.mode == EDIT_MODE:
              return False
          for combo_box in self.exposure_combo_boxes:
              # Enable if there is one that has classification
              if combo_box.currentIndex() > 0:
                  return True
          # Trick for EQ raster for population #3853
          if self.use_default_thresholds:
              return True
          return False
docs: Check if the step is complete.
  
          :returns: True if new step may be enabled.
          :rtype: bool