import org.jetbrains.annotations.*; class Test { <warning descr="Not-null fields must be initialized">@NotNull</warning> Object member; <warning descr="Not-null fields must be initialized">@NotNull</warning> Object member2; public Test(Object p) { I i = param -> { member = param; }; I i2 = new I() { @Override public void foo(Object param) { member2 = param; } }; i.foo(p); i2.foo(p); } } interface I { void foo(Object param); }