This method returns future bookings for a user at any merchant. This method
should not return past bookings or cancelled bookings.

**Request**

ListBookingsRequest

**Return value**

ListBookingsResponse

```protobuf
// Request to list all bookings for a user
export message ListBookingsRequest {
  option features.(pb.java).nest_in_file_class = YES;

  // ID of the user (required)
  string user_id = 1 [
    features.field_presence = IMPLICIT,
    features.(pb.cpp).string_type = STRING
  ];
}

// Response for the ListBookings RPC with all bookings for the requested user.
export message ListBookingsResponse {
  option features.(pb.java).nest_in_file_class = YES;

  // All bookings of the user (required)
  repeated Booking bookings = 1;
}
```