Nullability is apparently not checked in initializers for static fields. See the two occurrences of "new TestConstantConditions(null)" below – only one of them generates a warning.

package test;

import org.jetbrains.annotations.NotNull;

public class TestConstantConditions
{
static Object obj =    new TestConstantConditions(null); // No warning
TestConstantConditions(@NotNull Object obj) { }
void test() { new TestConstantConditions(null); } // Warning
}