docs: public void fieldsToBuffer(FieldList record, int iFieldsTypes)
      {
          m_iFieldsTypes = iFieldsTypes;
          if (this.getHeaderCount() == 0)
              this.clearBuffer();   // Being careful. (Remember to call this at the start anyway)
          int fieldCount = record.getFieldCount();    // Number of fields to write out
          for (int iFieldSeq = Constants.MAIN_FIELD; iFieldSeq <= fieldCount + Constants.MAIN_FIELD - 1; iFieldSeq++)
          {
              FieldInfo field = record.getField(iFieldSeq);
              if (!this.skipField(field))
                  this.addNextField(field);
          }
          this.finishBuffer();    //pDestBuff, recordLength, physicalFieldCount);   // two bytes for record length, two for field count
      }