docs: def _reset_stylesheet(self):
          """ Resets stylesheet"""
          self.setFont(QtGui.QFont(self._font_family,
                                   self._font_size + self._zoom_level))
          flg_stylesheet = hasattr(self, '_flg_stylesheet')
          if QtWidgets.QApplication.instance().styleSheet() or flg_stylesheet:
              self._flg_stylesheet = True
              # On Window, if the application once had a stylesheet, we must
              # keep on using a stylesheet otherwise strange colors appear
              # see https://github.com/OpenCobolIDE/OpenCobolIDE/issues/65
              # Also happen on plasma 5
              try:
                  plasma = os.environ['DESKTOP_SESSION'] == 'plasma'
              except KeyError:
                  plasma = False
              if sys.platform == 'win32' or plasma:
                  self.setStyleSheet('''QPlainTextEdit
                  {
                      background-color: %s;
                      color: %s;
                  }
                  ''' % (self.background.name(), self.foreground.name()))
              else:
                  # on linux/osx we just have to set an empty stylesheet to
                  # cancel any previous stylesheet and still keep a correct
                  # style for scrollbars
                  self.setStyleSheet('')
          else:
              p = self.palette()
              p.setColor(QtGui.QPalette.Base, self.background)
              p.setColor(QtGui.QPalette.Text, self.foreground)
              p.setColor(QtGui.QPalette.Highlight,
                         self.selection_background)
              p.setColor(QtGui.QPalette.HighlightedText,
                         self.selection_foreground)
              self.setPalette(p)
          self.repaint()