def _getFontChars(self, font_files):
code_points = set()<EOL>for font_file in font_files:<EOL><INDENT>face = ft.Face(font_file)<EOL>charcode, agindex = face.get_first_char()<EOL>while agindex != <NUM_LIT:0>:<EOL><INDENT>code_points.add(charcode)<EOL>charcode, agindex = face.get_next_char(charcode, agindex)<EOL><DEDENT><DEDENT>return sorted(code_points)<EOL>
Returns code points of characters included in given font files.