Sets the variable button true state.

def __set_true_state(self):
        """
        Sets the variable button true state.
        """

        LOGGER.debug("> Setting variable QPushButton() to 'True' state.")
        self.__state = True

        palette = QPalette()
        palette.setColor(QPalette.Button, foundations.common.get_first_item(self.__colors))
        self.setPalette(palette)

        self.setChecked(True)
        self.setText(foundations.common.get_first_item(self.__labels))