question: public String put ( String key , String value , boolean percentEncode ) { SortedSet < String > values = wrappedMap . get ( key ) ; if ( values == null ) { values = new TreeSet < String > ( ) ; wrappedMap . put ( percentEncode ? OAuth . percentEncode ( key ) : key , values ) ; } if ( value != null ) { value = percentEncode ? OAuth . percentEncode ( value ) : value ; values . add ( value ) ; } return value ; }
target:  Convenience method to add a single value for the parameter specified by 'key'.