Optional checker: possible erroneous report of an incompatible method receiver for `Optional#get` in a `Stream#map`

Summary

Running the Optional checker on code that contains a call to Optional#get within a call to .map on a Java stream produces an error reporting to an incompatible method receiver.

Commands executed

Using the latest commit on the master branch of the Checker Framework, where javacheck is an alias for javac included in the Checker Framework's binary distribution.

javacheck -processor optional Main.java

Input

This is a minimal test case that should be able to trigger this issue

import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;

public class Main {

  public List<Integer> getOnlyPresentInts(List<Optional<Integer>> optInts) {
    return optInts.stream()
      .map(Optional::get)
      .collect(Collectors.toList());
  }
}

Actual output

Main.java:9: warning: [optional.as.element.type] Don't use Optional as the element type in a collection.
  public List<Integer> getOnlyPresentInts(List<Optional<Integer>> optInts) {
                                                                  ^
Main.java:11: error: [methodref.receiver] Incompatible receiver type
      .map(Optional::get)
           ^
  found   : @Present Optional<@MaybePresent Integer>
  required: @MaybePresent Optional<@MaybePresent Integer>
  Consequence: method in @MaybePresent Optional<@MaybePresent Integer>
    @MaybePresent Integer get(@Present Optional<@MaybePresent Integer> this)
  is not a valid method reference for method in @MaybePresent Function<@MaybePresent Optional<@MaybePresent Integer>, @MaybePresent Integer>
    @MaybePresent Integer apply(@MaybePresent Function<@MaybePresent Optional<@MaybePresent Integer>, @MaybePresent Integer> this, @MaybePresent Optional<@MaybePresent Integer> p0)
1 error
1 warning

Expected output

There should technically be no error about an incompatible method receiver, as calling .stream() on an object of type List<Optional<Integer>> should evaluate to an object of type Stream<Optional<Integer>>.

Additionally, the error line

Main.java:11: error: [methodref.receiver] Incompatible receiver type
      .map(Optional::get)
           ^
  found   : @Present Optional<@MaybePresent Integer>
  required: @MaybePresent Optional<@MaybePresent Integer>

Is confusing to me, shouldn't the found type be annotated with @MaybePresent? Since the manual states

@MaybePresent
The annotated Optional container may or may not contain a value. This is the default type, so programmers do not have to
write it.

However, this might be a misunderstanding of the Optional checker's type system on my part.