if (headers != null) {
            final Map<String, List<String>> map = new HashMap<>();
            headers.entrySet().stream().filter(e -> e.getKey() != null)
                    .forEach(e -> map.put(e.getKey().toLowerCase(Locale.ROOT), e.getValue()));
            this.headers = map;
        }
    }

    public Map<String, List<String>> getHeaders() {
        return headers;
    }

            if (metadata instanceof VersionsMetadata) {
                it.remove();
                VersionsMetadata versionsMetadata = (VersionsMetadata) metadata;
                processedVersions.put(versionsMetadata.getKey(), versionsMetadata);
            }
        }
    }

    @Override
    public Collection<? extends Metadata> prepare(Collection<? extends Artifact> artifacts) {
        return Collections.emptyList();
    }

    Map<K, V> delegate = Maps.newLinkedHashMap();
    for (Entry<? extends K, ? extends V> entry : entries) {
      K key = checkNotNull(entry.getKey());
      V previous = delegate.put(key, checkNotNull(entry.getValue()));
      if (throwIfDuplicateKeys && previous != null) {
        throw new IllegalArgumentException("duplicate key: " + key);
      }
    }

        } else if (Constants.NTLM.equals(scheme)) {
            final Properties props = new Properties();
            paramMap.entrySet().stream().filter(e -> e.getKey().startsWith("jcifs.")).forEach(e -> {
                props.setProperty(e.getKey(), e.getValue());
            });
            authScheme = new NTLMScheme(new JcifsEngine(props));
        } else if (Constants.FORM.equals(scheme)) {

                    logger.warn("Could not parse a value of " + entry.getKey() + ":" + entry.getValue(), e);
                }
                if (nodeStrList.size() == 1) {
                    buf.append(getResultDataBody(entry.getKey(), nodeStrList.get(0)));
                } else if (nodeStrList.size() > 1) {
                    buf.append(getResultDataBody(entry.getKey(), nodeStrList));
                }
            }

                buf.append('{');
                boolean first2 = true;
                for (final Map.Entry<String, Object> entry : doc.entrySet()) {
                    final String name = entry.getKey();
                    if (StringUtil.isNotBlank(name) && entry.getValue() != null) {
                        if (!first2) {
                            buf.append(',');
                        } else {

      assertSame(keyOne, entryOne.getKey());
      assertEquals(hashOne, entryOne.getHash());
      assertNull(entryOne.getNext());
      assertSame(valueOne, copyOne.getValueReference().get());
      assertConnected(map, copyOne, entryTwo);

      ReferenceEntry<Object, Object> copyTwo = map.copyEntry(entryTwo, copyOne);
      assertSame(keyTwo, copyTwo.getKey());
      assertEquals(hashTwo, copyTwo.getHash());

    Multimap<K, V> multimap = multimap();
    assertEquals(expectedSize, multimap.size());

    int size = 0;
    for (Entry<K, V> entry : multimap.entries()) {
      assertTrue(multimap.containsEntry(entry.getKey(), entry.getValue()));
      size++;
    }
    assertEquals(expectedSize, size);

    int size2 = 0;
    for (Entry<K, Collection<V>> entry2 : multimap.asMap().entrySet()) {
      size2 += entry2.getValue().size();

    assertFalse(map.containsKey(getKey));
    assertSame(refreshKey, map.get(refreshKey));

    // let computation complete
    letGetFinishSignal.countDown();
    getFinishedSignal.await();
    checkNothingLogged();

    // asMap view should have been updated
    assertEquals(2, cache.size());
    assertEquals(getKey + suffix, map.get(getKey));

    Entry<String, Collection<Integer>> entry = iterator.next();
    assertEquals(null, entry.getKey());
    assertThat(entry.getValue()).containsExactly(7, 3, 1);
    entry = iterator.next();
    assertEquals("tree", entry.getKey());
    assertThat(entry.getValue()).containsExactly(null, 0);
    entry = iterator.next();
    assertEquals("google", entry.getKey());
    assertThat(entry.getValue()).containsExactly(6, 2);
  }