266     max_count = None  variable in UnstructuredHeader
277     max_count = 1  variable in UniqueUnstructuredHeader
291     max_count = None  variable in DateHeader
321     max_count = 1  variable in UniqueDateHeader
326     max_count = None  variable in AddressHeader
381     max_count = 1  variable in UniqueAddressHeader
396     max_count = 1  variable in UniqueSingleAddressHeader
401     max_count = 1  variable in MIMEVersionHeader
441     max_count = 1  variable in ParameterizedMIMEHeader
503     max_count = 1  variable in ContentTransferEncodingHeader
524     max_count = 1  variable in MessageIDHeader