code: public TemplateInformation listTemplatesForDocument(String accountId, String envelopeId, String documentId) throws ApiException {
      return listTemplatesForDocument(accountId, envelopeId, documentId, null);
    }
docs: Gets the templates associated with a document in an existing envelope.
  Retrieves the templates associated with a document in the specified envelope.
  @param accountId The external account number (int) or account ID Guid. (required)
  @param envelopeId The envelopeId Guid of the envelope being accessed. (required)
  @param documentId The ID of the document being accessed. (required)
  @return TemplateInformation