checker/tests/nullness/java8/lambda/Issue3217.java

import java.util.function.Function;
import org.checkerframework.checker.nullness.qual.Nullable;

public class Issue3217<ModelA, ModelB, Value> {
  private final Function<Function<ModelA, @Nullable Value>, Function<ModelB, @Nullable Value>>
      proxyFunction;

  public Issue3217(
      Function<Function<ModelA, @Nullable Value>, Function<ModelB, @Nullable Value>>
          proxyFunction) {
    this.proxyFunction = proxyFunction;
  }
}

class SubClass<A, V> extends Issue3217<A, A, V> {
  public SubClass() {
    super(x -> x);
    Function<Function<A, @Nullable V>, Function<A, @Nullable V>> p = y -> y;
  }
}