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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 remove_last_line(self):
 """Removes the last line of the document."""

        editor = self._editor
        text_cursor = editor.textCursor()
        text_cursor.movePosition(text_cursor.End, text_cursor.MoveAnchor)
        text_cursor.select(text_cursor.LineUnderCursor)
        text_cursor.removeSelectedText()
        text_cursor.deletePreviousChar()
        editor.setTextCursor(text_cursor)