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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 _select_word_cursor(self):
 """ Selects the word under the mouse cursor. """

        cursor = TextHelper(self.editor).word_under_mouse_cursor()
        if (self._previous_cursor_start != cursor.selectionStart() and
                self._previous_cursor_end != cursor.selectionEnd()):
            self._remove_decoration()
            self._add_decoration(cursor)
        self._previous_cursor_start = cursor.selectionStart()
        self._previous_cursor_end = cursor.selectionEnd()