Overriden to take default database and save locally

        The issue was that init_default() sets self.filename to None; however there can be no
        SQLite database without a corresponding file (not using *memory* here)

        Should not keep default file open either (as it is in the API directory and shouldn't be
        messed by user)

def init_default(self):
        """Overriden to take default database and save locally

        The issue was that init_default() sets self.filename to None; however there can be no
        SQLite database without a corresponding file (not using *memory* here)

        Should not keep default file open either (as it is in the API directory and shouldn't be
        messed by user)
        """
        import f311
        if self.default_filename is None:
            raise RuntimeError("Class '{}' has no default filename".format(self.__class__.__name__))
        fullpath = f311.get_default_data_path(self.default_filename, class_=self.__class__)
        self.load(fullpath)
        name, ext = os.path.splitext(self.default_filename)
        new = a99.new_filename(os.path.join("./", name), ext)
        self.save_as(new)