// Issue 1142 https://github.com/typetools/checker-framework/issues/1142

import java.util.concurrent.ConcurrentHashMap;
import org.checkerframework.checker.nullness.qual.Nullable;

public class Issue1142 {

  void foo() {
    // :: error: (type.argument)
    ConcurrentHashMap<Integer, @Nullable Integer> chm1 = new ConcurrentHashMap<>();
    chm1.put(1, null);
  }
}