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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def leave_command_mode(self, append_to_history=False):
 """ Leave command mode. Focus document window again. """

        self.previewer.restore()

        self.application.layout.focus_last()
        self.application.vi_state.input_mode = InputMode.NAVIGATION

        self.command_buffer.reset(append_to_history=append_to_history)