def _font_of_mention(m):
for ch in m:<EOL><INDENT>if isinstance(ch, LTChar) and ch.get_text().isalnum():<EOL><INDENT>return (ch.fontname, _font_size_of(ch))<EOL><DEDENT><DEDENT>return (None, <NUM_LIT:0>)<EOL>
Returns the font type and size of the first alphanumeric
char in the text or None if there isn't any.