result = repoSystem.resolveArtifact(session, artifactRequest);
            } catch (ComponentLookupException e) {
                throw new IllegalStateException("Unable to lookup " + RepositorySystem.class.getName());
            } catch (org.eclipse.aether.resolution.ArtifactResolutionException e) {

_2025-07-07_

 *  New: `Response.peekTrailers()`. When we changed `Response.trailers()` to block instead of
    throwing in 5.0.0, we inadvertently removed the ability for callers to peek the trailers
    (by catching the `IllegalStateException` if they weren't available). This new API restores that
    capability.

 *  Fix: Don't crash on `trailers()` if the response doesn't have a body. We broke [Retrofit] users

      // We want remove() to fail even after a failed call to next().
    }
    assertThrows(IllegalStateException.class, () -> iterator.remove());
  }

  public void testSkip_allOfMutableList_modifiable() {
    List<String> list = newArrayList("a", "b");
    Iterator<String> iterator = skip(list, 2).iterator();
    assertThrows(IllegalStateException.class, () -> iterator.remove());
  }

    ImmutableBiMap.Builder<String, Integer> builder =
        new Builder<String, Integer>().orderEntriesByValue(Ordering.natural());
    assertThrows(
        IllegalStateException.class, () -> builder.orderEntriesByValue(Ordering.natural()));
  }

  public void testBuilderPutAllWithEmptyMap() {
    ImmutableBiMap<String, Integer> map =

                removeIdleConnections();

                // If still at limit, throw exception
                if (this.connections.size() >= maxPoolSize) {
                    throw new IllegalStateException("Connection pool has reached maximum size of " + maxPoolSize
                            + ". Consider increasing pool size or closing idle connections.");
                }
            }
        }

  }

  public void testGetCharset_tooMany() {
    MediaType mediaType = MediaType.parse("text/plain; charset=utf-8; charset=utf-16");
    assertThrows(IllegalStateException.class, mediaType::charset);
  }

  public void testGetCharset_illegalCharset() {
    MediaType mediaType = MediaType.parse("text/plain; charset=\"!@#$%^&*()\"");

        final BulkItemResponse[] itemResponses = response.getItems();
        if (itemResponses.length != entityList.size()) {
            throw new IllegalStateException("Invalid response size: " + itemResponses.length + " != " + entityList.size());
        }
        final int[] results = new int[itemResponses.length];
        for (int i = 0; i < itemResponses.length; i++) {

        final BulkItemResponse[] itemResponses = response.getItems();
        if (itemResponses.length != entityList.size()) {
            throw new IllegalStateException("Invalid response size: " + itemResponses.length + " != " + entityList.size());
        }
        final int[] results = new int[itemResponses.length];
        for (int i = 0; i < itemResponses.length; i++) {

            writeSecurityBuffer(type3, 52, offset, sessionKey);
            writeULong(type3, 60, flags);
            return type3;
        } catch (final IOException ex) {
            throw new IllegalStateException(ex.getMessage());
        }
    }

    @Override
    public String toString() {
        final String user = getUser();
        final String domain = getDomain();

        .build(),
    )
    val response1 = get(server.url("/"))
    val source = response1.body.source()
    assertThat(source.readUtf8(5)).isEqualTo("ABCDE")
    source.close()
    assertFailsWith<IllegalStateException> {
      source.readByte()
    }
    assertThat(cache.writeAbortCount()).isEqualTo(1)
    assertThat(cache.writeSuccessCount()).isEqualTo(0)
    val response2 = get(server.url("/"))