def get_ledger_code_to_guid_map(self, codes):
if codes:<EOL><INDENT>codes = set(str(i) for i in codes)<EOL>ledger_ids = self._api.ledgeraccounts.filter(code__in=codes)<EOL>ret = dict((str(i['<STR_LIT>']), i['<STR_LIT>']) for i in ledger_ids)<EOL>found = set(ret.keys())<EOL>missing = (codes - found)<EOL>if missing:<EOL><INDENT>raise UnknownLedgerCodes(missing)<EOL><DEDENT>return ret<EOL><DEDENT>return {}<EOL>
Convert set of human codes and to a dict of code to exactonline
guid mappings.

Example::

    ret = inv.get_ledger_code_to_guid_map(['1234', '5555'])
    ret == {'1234': '<guid1_from_exactonline_ledgeraccounts>',
            '5555': '<guid2_from_exactonline_ledgeraccounts>'}