import java.util.function.Supplier; class Test { { Object o = true ? ((Supplier<String>) () -> "") : null; Supplier<String> s1 = true ? ((<warning descr="Casting '() -> \"\"' to 'Supplier<String>' is redundant">Supplier<String></warning>) () -> "") : null; Supplier<String> s2 = true ? ((A) () -> "") : null; } interface A extends Supplier<String> {} }