Tuple original = new Tuple( "john", "doe" );

// call copy constructor
Tuple copy = new Tuple( original );

assert copy.get( 0 ).equals( "john" );

Tuple parent = new Tuple();
parent.add( new Tuple( "john", "doe" ) );

assert ( (Tuple) parent.get( 0 ) ).get( 0 ).equals( "john" );

Fields first = new Fields( "first" );
Fields middle = new Fields( "middle" );
Fields last = new Fields( "last" );

Fields full = first.append( middle ).append( last );

Fields full = new Fields( "first", "middle", "last" );

Fields firstLast = full.subtract( new Fields( "middle" ) );