code: public RecipientsUpdateSummary updateRecipients(String accountId, String envelopeId, Recipients recipients) throws ApiException {
      return updateRecipients(accountId, envelopeId, recipients, null);
    }
docs: Updates recipients in a draft envelope or corrects recipient information for an in process envelope.
  Updates recipients in a draft envelope or corrects recipient information for an in process envelope.   For draft envelopes, you can edit the following properties: &#x60;email&#x60;, &#x60;userName&#x60;, &#x60;routingOrder&#x60;, &#x60;faxNumber&#x60;, &#x60;deliveryMethod&#x60;, &#x60;accessCode&#x60;, and &#x60;requireIdLookup&#x60;.  Once an envelope has been sent, you can only edit: &#x60;email&#x60;, &#x60;userName&#x60;, &#x60;signerName&#x60;, &#x60;routingOrder&#x60;, &#x60;faxNumber&#x60;, and &#x60;deliveryMethod&#x60;. You can also select to resend an envelope by using the &#x60;resend_envelope&#x60; option.  If you send information for a recipient that does not already exist in a draft envelope, the recipient is added to the envelope (similar to the POST).
  @param accountId The external account number (int) or account ID Guid. (required)
  @param envelopeId The envelopeId Guid of the envelope being accessed. (required)
  @param recipients  (optional)
  @return RecipientsUpdateSummary