def __init__(self, groups=None):
        super(GroupedRequirements, self).__init__(NamedRequirements)
        self.groups = groups or self.default_groups
        self.filename = None
        self.create_default_groups()
def gettext(self, text: str, lang: str = None):
        """
        Singular translations
        """

        if lang is None:
            lang = self.context_lang.get()

        if lang not in self.translations:
            return text

        translator = self.translations[lang]
        return translator.gettext(text)