code: public WriteConcern withW(final int w) {
          return new WriteConcern(Integer.valueOf(w), wTimeoutMS, fsync, journal);
      }
docs: Constructs a new WriteConcern from the current one and the specified integer-based value for w
  
  @param w number of servers to ensure write propagation to before acknowledgment, which must be {@code >= 0}
  @return the new WriteConcern
  @mongodb.driver.manual core/write-concern/#replica-acknowledged Replica Acknowledged