question: public JSONObject toJSON ( ) throws JSONException { JSONObject json = new JSONObject ( ) ; if ( entries . size ( ) > 0 ) { JSONObject history = new JSONObject ( ) ; for ( Entry e : entries ) { history . put ( e . pushId , e . timestamp ) ; } json . put ( "seen" , history ) ; } json . putOpt ( "lastTime" , lastTime ) ; return json ; }
target:  Serializes the history state to a JSON object using the format described in loadJSON().