code: @InterfaceAudience.Public
      public void start() {
  
          if (runningState.get() == true) {
              Log.v(Log.TAG_QUERY, "%s: start() called, but runningState is already true.  Ignoring.", this);
              return;
          } else {
              Log.d(Log.TAG_QUERY, "%s: start() called", this);
              runningState.set(true);
          }
  
          if (!observing) {
              observing = true;
              getDatabase().addChangeListener(this);
              Log.v(Log.TAG_QUERY, "%s: start() is calling update()", this);
              update();
          }
      }
docs: Starts observing database changes. The .rows property will now update automatically. (You
  usually don't need to call this yourself, since calling getRows() will start it for you