code: @CheckResult protected Observable<Long> insert(final String table, final ContentValues contentValues) {
      return Observable.defer(new Func0<Observable<Long>>() {
        @Override
        public Observable<Long> call() {
          return Observable.just(db.insert(table, contentValues));
        }
      });
    }
docs: Insert a row into the given table
  
  @param table the table name
  @param contentValues The content values
  @return An <b>deferred</b> observable with the row Id of the new inserted row