def coerce(cls, string):
        """Create a :class:`Requirement` object from a given package spec."""
        match = re.match(cls.spec_regex, string)
        if not match:
            raise InvalidRequirementSpecError("could not parse requirement")
        package = match.group(1)
        if all(match.group(2, 3)):
            version = "".join(match.group(2, 3))
        else:
            version = None
        return cls(package, version)
def on_fuzz_msg_changed(self, index: int):
        self.ui.comboBoxFuzzingLabel.setDisabled(False)

        sel_label_ind = self.ui.comboBoxFuzzingLabel.currentIndex()
        self.ui.comboBoxFuzzingLabel.blockSignals(True)
        self.ui.comboBoxFuzzingLabel.clear()

        if len(self.message.message_type) == 0:
            self.ui.comboBoxFuzzingLabel.setDisabled(True)
            return

        self.ui.comboBoxFuzzingLabel.addItems([lbl.name for lbl in self.message.message_type])
        self.ui.comboBoxFuzzingLabel.blockSignals(False)

        if sel_label_ind < self.ui.comboBoxFuzzingLabel.count():
            self.ui.comboBoxFuzzingLabel.setCurrentIndex(sel_label_ind)
        else:
            self.ui.comboBoxFuzzingLabel.setCurrentIndex(0)

        self.fuzz_table_model.fuzzing_label = self.current_label
        self.fuzz_table_model.update()
        self.update_message_data_string()