public static void Log(String format, Object ... args) {
    final Object[] fmt = new Object[ args.length ];
        for(int i = 0; i < args.length; i++)
            fmt[i] = args[i] instanceof Supplier  ?
                     ( (Supplier) args[i] ).get() :
                     args[i];
    final String s = String.format( format, fmt );
    System.err.println( s );
}

final Supplier
    s = () -> "aaa",
    d = () -> 111;
Log( "%s %d %s %d", "bbb", 222, s, d );    // OK, OUTPUT: bbb 222 aaa 111
Log( "%s %d %s %d", "bbb", 222, () -> "aaa", () -> 111 );  // COMPILE FAIL

Log( "%s %d %s %d", "bbb", 222, (Supplier) () -> "aaa", (Supplier) () -> 111 );

Log( "%s %d %s %d", "bbb", 222, (Callable) () -> "aaa", (Callable) () -> 111 );

Log( "%s %d %s %d", "bbb", 222, ((Supplier<String>)() -> "aaa"), ((Suplier<Integer>)() -> 111) );

Log( "%s %d %s %d", "bbb", 222, new Supplier<String>() {
            @Override
            public String get() {
                return "aaa";
            }
        });

Log( "%s %d %s %d", "bbb", 222, (Supplier<String>) () -> "aaa");