question: Builder addQueryParameter ( String name , String value ) { if ( name == null ) throw new IllegalArgumentException ( "name == null" ) ; if ( encodedQueryNamesAndValues == null ) encodedQueryNamesAndValues = new ArrayList < > ( ) ; encodedQueryNamesAndValues . add ( canonicalize ( name , QUERY_COMPONENT_ENCODE_SET , false , true ) ) ; encodedQueryNamesAndValues . add ( value != null ? canonicalize ( value , QUERY_COMPONENT_ENCODE_SET , false , true ) : null ) ; return this ; }
target:  Encodes the query parameter using UTF-8 and adds it to this URL's query string. 