def _parse_section(token_iter):
sexp = []<EOL>for token in token_iter:<EOL><INDENT>if token == '<STR_LIT:(>':<EOL><INDENT>new_sexp = _parse_section(token_iter)<EOL>if not _match_section(new_sexp, UNWANTED_SECTIONS):<EOL><INDENT>sexp.append(new_sexp)<EOL><DEDENT><DEDENT>elif token == '<STR_LIT:)>':<EOL><INDENT>return sexp<EOL><DEDENT>else:<EOL><INDENT>sexp.append(token)<EOL><DEDENT><DEDENT>return sexp<EOL>
take a stream of tokens, and create the tree structure that is defined
    by the s-expressions