code: private void addPartNumberIfNotNull(Request<?> request, Integer partNumber) {
          if (partNumber != null) {
              request.addParameter("partNumber", partNumber.toString());
          }
      }
docs: Adds the part number to the specified request, if partNumber is not null.
  
  @param request
  The request to add the partNumber to.
  @param partNumber
  The part number to be added.