code: @Override
      public EmailSendConfig[] listEmailConfig(String CorpNum, String UserID) throws PopbillException {
          return httpget("/Taxinvoice/EmailSendConfig", CorpNum, UserID, EmailSendConfig[].class);
      }
docs: /*
  (non-Javadoc)
  @see com.popbill.api.TaxinvoiceService#listEmailConfig(java.lang.String, java.lang.String)