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import java.util.stream.Stream;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.Optional;
 
class Interesting {
  public <T> Optional<? extends Predicate<? super T>> with(Stream<Predicate<? super T>> predicates) {
    return predicates.map(Function.identity()).reduce(Predicate::or);
  }
 
  public static void main(String[] args) {}
}

Main.java:8: error: incompatible types: invalid method reference
    return predicates.map(Function.identity()).reduce(Predicate::or);
                                                      ^
    incompatible types: Predicate<CAP#1> cannot be converted to Predicate<? super CAP#2>
  where T is a type-variable:
    T extends Object declared in method <T>with(Stream<Predicate<? super T>>)
  where CAP#1,CAP#2 are fresh type-variables:
    CAP#1 extends Object super: T from capture of ? super T
    CAP#2 extends Object super: T from capture of ? super T
Note: Some messages have been simplified; recompile with -Xdiags:verbose to get full output
1 error

Standard output is empty