builds with JDK8 began failing animal-sniffer with the error:

                   Failed to check signatures: Bad class file .../CollectionFuture$ListFuture.class

                   One way of dealing with that would be to disable
                   animal-sniffer. And that would be fine for our -jre builds:

      MultipartBody.Builder("boundary")
        .setType(MultipartBody.PARALLEL)
        .addPart("Quick".toRequestBody("text/plain".toMediaType()))
        .addFormDataPart("color", "Brown")
        .addFormDataPart("animal", "fox.txt", "Fox".toRequestBody())
        .build()

    val bodyContent = Buffer()
    body.writeTo(bodyContent)

    val reader = MultipartReader(bodyContent, "boundary")

        EnumSetAccumulator::combine,
        EnumSetAccumulator::toImmutableSet,
        Collector.Characteristics.UNORDERED);
  }

  @IgnoreJRERequirement // see enclosing class (whose annotation Animal Sniffer ignores here...)
  private static final class EnumSetAccumulator<E extends Enum<E>> {
    @SuppressWarnings({"rawtypes", "unchecked"})

import okhttp3.internal.tls.BasicTrustRootIndex
import okhttp3.internal.tls.CertificateChainCleaner
import okhttp3.internal.tls.TrustRootIndex
import okio.Buffer
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

/**
 * Access to platform-specific features.
 *
 * ### Session Tickets
 *
 * Supported on Android 2.3+.
 * Supported on JDK 8+ via Conscrypt.
 *

              /* prefix= */ prefix,
              /* suffix= */ null,
              filePermissions.get())
          .toFile();
    }

    @IgnoreJRERequirement // see enclosing class (whose annotation Animal Sniffer ignores here...)
    private interface PermissionSupplier {
      FileAttribute<?> get() throws IOException;
    }

    private static final PermissionSupplier filePermissions;

import okhttp3.internal.commonValue
import okhttp3.internal.commonValues
import okhttp3.internal.headersCheckName
import okhttp3.internal.http.toHttpDateOrNull
import okhttp3.internal.http.toHttpDateString
import org.codehaus.mojo.animal_sniffer.IgnoreJRERequirement

/**
 * The header fields of a single HTTP message. Values are uninterpreted strings; use `Request` and

  /*
   * If we make these calls inline inside toImmutableSortedMultiset, we get an Animal Sniffer error,
   * despite the @IgnoreJRERequirement annotation there. My assumption is that, because javac
   * generates a synthetic method for the body of the lambda, the actual method calls that Animal
   * Sniffer is flagging don't appear inside toImmutableSortedMultiset but rather inside that

    avatarUrl: https://avatars.githubusercontent.com/u/3634801?u=eaadda178c964178fcb64886f6c732172c8f8219&v=4
    url: https://github.com/aacayaco
  - login: anomaly
    avatarUrl: https://avatars.githubusercontent.com/u/3654837?v=4
    url: https://github.com/anomaly
  - login: jgreys
    avatarUrl: https://avatars.githubusercontent.com/u/4136890?u=096820d1ef89877d57d0f68e669ead8b0fde84df&v=4
    url: https://github.com/jgreys

   */
  @SuppressWarnings({"AndroidJdkLibsChecker", "Java7ApiChecker"})
  // @IgnoreJRERequirement is not necessary because this compiles down to a constant.
  // (which is fortunate because Animal Sniffer doesn't look for @IgnoreJRERequirement on fields)
  static final int SPLITERATOR_CHARACTERISTICS =
      Spliterator.IMMUTABLE | Spliterator.NONNULL | Spliterator.ORDERED;

  ImmutableCollection() {}

Tatsächlich funktionieren alle (oder die meisten) Webframeworks auf die gleiche Weise.

Sie rufen diese Funktionen niemals direkt auf. Sie werden von Ihrem Framework aufgerufen (in diesem Fall **FastAPI**).