import java.io.BufferedReader; import java.io.FileReader; import java.io.IOException; class Test { { if (Test::length instanceof String) { } bar(Test::length); } public static Integer length(String s) { return s.length(); } public static void bar(Bar bar) {} interface Bar { Integer m(String s); } void f() throws IOException { try (BufferedReader reader = new BufferedReader(new FileReader(""))) { for (String line : reader::lines) {} } } }