framework/tests/all-systems/java8inference/Bug7.java

package inference.guava;

import java.io.Serializable;
import java.util.Map;
import java.util.function.Function;
import java.util.stream.Collector;

@SuppressWarnings("all") // Just check for crashes.
public class Bug7 {
  static <T, K, V> Collector<T, ?, MyMap<K, V>> toMap(
      Function<? super T, ? extends K> keyFunction,
      Function<? super T, ? extends V> valueFunction) {
    return Collector.of(
        MyMap.Builder<K, V>::new,
        (builder, input) -> builder.put(keyFunction.apply(input), valueFunction.apply(input)),
        MyMap.Builder::combine,
        MyMap.Builder::build);
  }

  public abstract static class MyMap<K, V> implements Map<K, V>, Serializable {
    public static class Builder<K, V> {

      public Builder() {}

      public Builder<K, V> put(K key, V value) {
        throw new RuntimeException();
      }

      Builder<K, V> combine(Builder<K, V> other) {
        throw new RuntimeException();
      }

      public MyMap<K, V> build() {
        throw new RuntimeException();
      }
    }
  }
}