old_contents: from PyQt5.QtWebEngineWidgets import QWebEngineView
  import core_interface
  
  
  class Minibuffer(QWebEngineView):
      """Documentation for Minibuffer
  
      """
      scripts = {}
      callback_count = 0
      window_identifier = 0
  
      def __init__(self, window_identifier, parent=None):
          super(Minibuffer, self).__init__(parent)
          self.window_identifier = window_identifier
          self.setHtml("")  # breaks without this line
  
      def evaluate_javascript(self, script):
          """
          This method returns an identifier (str) to the LISP core. Upon
          completion of the javascript script, the platform port will
          make a call to the LISP core with the results of that
          computation, and the associated identifier.
  
          :param script: the JavaScript script to execute
          :returns: a callback_id
          :rtype: string
          """
          self.callback_count += 1
          self.page().runJavaScript(
              script,
              lambda x: self.javascript_callback(x, str(self.callback_count)))
          return str(self.callback_count)
  
      def javascript_callback(self, res, callback_id):
          if res is None:
              return
          core_interface.minibuffer_javascript_call_back(str(self.window_identifier), res, callback_id)
  
      def set_height(self, height):
          self.setFixedHeight(height)
  
new_contents: from PyQt5.QtWebEngineWidgets import QWebEngineView
  import core_interface
  
  
  class Minibuffer(QWebEngineView):
      """Documentation for Minibuffer
  
      """
      scripts = {}
      callback_count = 0
      window_identifier = 0
  
      def __init__(self, window_identifier, parent=None):
          super(Minibuffer, self).__init__(parent)
          self.window_identifier = window_identifier
  
      def evaluate_javascript(self, script):
          """
          This method returns an identifier (str) to the LISP core. Upon
          completion of the javascript script, the platform port will
          make a call to the LISP core with the results of that
          computation, and the associated identifier.
  
          :param script: the JavaScript script to execute
          :returns: a callback_id
          :rtype: string
          """
          self.callback_count += 1
          self.page().runJavaScript(
              script,
              lambda x: self.javascript_callback(x, str(self.callback_count)))
          return str(self.callback_count)
  
      def javascript_callback(self, res, callback_id):
          if res is None:
              return
          core_interface.minibuffer_javascript_call_back(str(self.window_identifier), res, callback_id)
  
      def set_height(self, height):
          self.setFixedHeight(height)
  
subject: remove unneeded line