docs: function callWebService( name, args, url ) {
      return new Promise(
          function( resolve, reject ) {
              svc( name, args, url ).then(
                  resolve,
                  function( err ) {
                      if ( typeof err === 'object' && err.id === exports.BAD_ROLE ) {
                          // Echec de connexion, on retente de se connecter avant d'abandonner.
                          login().then(
                              function() {
                                  svc( name, args, url ).then( resolve, reject );
                              },
                              reject
                          );
                      } else {
                          reject( err );
                      }
                  }
              );
          }
      );
  }