code: def _create_application(self):
          
          # Create Application.
          application = Application(
              input=self.input,
              output=self.output,
              editing_mode=EditingMode.VI,
              layout=self.editor_layout.layout,
              key_bindings=self.key_bindings,
  #            get_title=lambda: get_terminal_title(self),
              style=DynamicStyle(lambda: self.current_style),
              paste_mode=Condition(lambda: self.paste_mode),
  #            ignore_case=Condition(lambda: self.ignore_case),  # TODO
              include_default_pygments_style=False,
              mouse_support=Condition(lambda: self.enable_mouse_support),
              full_screen=True,
              enable_page_navigation_bindings=True)
  
          # Handle command line previews.
          # (e.g. when typing ':colorscheme blue', it should already show the
          # preview before pressing enter.)
          def preview(_):
              if self.application.layout.has_focus(self.command_buffer):
                  self.previewer.preview(self.command_buffer.text)
          self.command_buffer.on_text_changed += preview
  
          return application
docs: Create CommandLineInterface instance.