docs: function lockOperation(id) {
          return runner.run(function() {
              // Locking a locked operation should have no effect
              if (lockedOperationId === id) {
                  return;
              }
              
              if (!lockedOperationId) {
                  lockedOperationId = id;
                  return;
              }
  
              throw new Error('Only one operation can be locked at a time');
          });
      }