set the minor unit field for the axisoptions record .
229. HeaderRecord rec = new HeaderRecord();
230. rec.field_1_header_len = field_1_header_len;
231. rec.field_2_reserved = field_2_reserved;
232. rec.field_3_unicode_flag = field_3_unicode_flag;
233. rec.field_4_header = field_4_header;