Please get checker-qual and error_prone_annotations to agree with caffeine...update your check-qual dependency to 2.6.0 and your error_prone_annotations dependency to 2.3.3, please.

    Require upper bound dependencies error for org.checkerframework:checker-qua>
        +-com.google.guava:guava:27.1-jre (managed) <-- com.google.guava:guava:>
          +-org.checkerframework:checker-qual:2.5.2
    and
        +-com.github.ben-manes.caffeine:caffeine:2.7.0
          +-org.checkerframework:checker-qual:2.6.0

    Require upper bound dependencies error for com.google.errorprone:error_pron>
        +-com.google.guava:guava:27.1-jre (managed) <-- com.google.guava:guava:>
          +-com.google.errorprone:error_prone_annotations:2.2.0
    and
        +-com.github.ben-manes.caffeine:caffeine:2.7.0
          +-com.google.errorprone:error_prone_annotations:2.3.3

.put(Reader.class, new StringReader(""))
          .put(StringReader.class, new StringReader(""))
          .put(Buffer.class, ByteBuffer.allocate(0))
          .put(CharBuffer.class, CharBuffer.allocate(0))
          .put(ByteBuffer.class, ByteBuffer.allocate(0))
          .put(ShortBuffer.class, ShortBuffer.allocate(0))
          .put(IntBuffer.class, IntBuffer.allocate(0))
          .put(LongBuffer.class, LongBuffer.allocate(0))
          .put(FloatBuffer.class, FloatBuffer.allocate(0))
          .put(DoubleBuffer.class, DoubleBuffer.allocate(0))
          .put(File.class, new File(""))
          .put(ByteSource.class, ByteSource.empty())
          .put(CharSource.class, CharSource.empty())
          .put(ByteSink.class, NullByteSink.INSTANCE)
          .put(CharSink.class, NullByteSink.INSTANCE.asCharSink(Charsets.UTF_8))
          
          .put(Iterator.class, ImmutableSet.of().iterator())
          .put(PeekingIterator.class, Iterators.peekingIterator(ImmutableSet.of().iterator()))
          .put(ListIterator.class, ImmutableList.of().listIterator())
          .put(Iterable.class, ImmutableSet.of())
          .put(Collection.class, ImmutableList.of())
          .put(ImmutableCollection.class, ImmutableList.of())
          .put(List.class, ImmutableList.of())
          .put(ImmutableList.class, ImmutableList.of())
          .put(Set.class, ImmutableSet.of())
          .put(ImmutableSet.class, ImmutableSet.of())
          .put(SortedSet.class, ImmutableSortedSet.of())
          .put(ImmutableSortedSet.class, ImmutableSortedSet.of())
          .put(NavigableSet.class, Sets.unmodifiableNavigableSet(Sets.newTreeSet()))
          .put(Map.class, ImmutableMap.of())