def _set_unicode(self, value):
        """
        Assign the primary unicode to the glyph.
        This will be an integer or None.

        Subclasses may override this method.
        """
        values = list(self.unicodes)
        if value in values:
            values.remove(value)
        values.insert(0, value)
        self.unicodes = values
Assign the primary unicode to the glyph.
        This will be an integer or None.

        Subclasses may override this method.