Returns font files containing given code point.

def _getCharFont(self, font_files, code_point):
        """
        Returns font files containing given code point.
        """
        return_font_files = []
        for font_file in font_files:
            face = ft.Face(font_file)
            if face.get_char_index(code_point):
                return_font_files.append(font_file)
        return return_font_files