assertThat(iia.indexOf(1)).isEqualTo(0);
    assertThat(iia.indexOf(8)).isEqualTo(5);
    assertThat(iia.indexOf(4)).isEqualTo(-1);
    assertThat(ImmutableDoubleArray.of(13).indexOf(13)).isEqualTo(0);
    assertThat(ImmutableDoubleArray.of().indexOf(21)).isEqualTo(-1);
    assertThat(iia.subArray(1, 5).indexOf(1)).isEqualTo(0);
  }

  public void testIndexOf_specialValues() {

    assertThat(Doubles.indexOf(ARRAY234, EMPTY)).isEqualTo(0);
    assertThat(Doubles.indexOf(EMPTY, ARRAY234)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY234, ARRAY1)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY1, ARRAY234)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY1, ARRAY1)).isEqualTo(0);
    assertThat(Doubles.indexOf(ARRAY234, ARRAY234)).isEqualTo(0);

    assertThat(Chars.indexOf(ARRAY1, ARRAY1)).isEqualTo(0);
    assertThat(Chars.indexOf(ARRAY234, ARRAY234)).isEqualTo(0);
    assertThat(Chars.indexOf(ARRAY234, new char[] {(char) 2, (char) 3})).isEqualTo(0);
    assertThat(Chars.indexOf(ARRAY234, new char[] {(char) 3, (char) 4})).isEqualTo(1);
    assertThat(Chars.indexOf(ARRAY234, new char[] {(char) 3})).isEqualTo(1);

            final int indexOf = field.indexOf(':');
            if (indexOf < 0) {
                return new Pair<>(field, null);
            }
            final String indexField = indexOf == 0 ? defaultField : field.substring(0, indexOf);
            final String extensionKey = field.substring(indexOf + 1);
            return new Pair<>(indexField, extensionKey);
        }
    }

  }

  public void testIndexOf() {
    assertThat(Ints.indexOf(EMPTY, (int) 1)).isEqualTo(-1);
    assertThat(Ints.indexOf(ARRAY1, (int) 2)).isEqualTo(-1);
    assertThat(Ints.indexOf(ARRAY234, (int) 1)).isEqualTo(-1);
    assertThat(Ints.indexOf(new int[] {(int) -1}, (int) -1)).isEqualTo(0);
    assertThat(Ints.indexOf(ARRAY234, (int) 2)).isEqualTo(0);
    assertThat(Ints.indexOf(ARRAY234, (int) 3)).isEqualTo(1);

);

suggester.indexer()
    .indexFromDocument(reader, 2, 100)  // threads=2, batch=100
    .getResponse();
```

### Index from Query Logs

```java
import org.codelibs.fess.suggest.index.contents.querylog.QueryLog;

// Add suggestions from search query logs
QueryLog queryLog = new QueryLog("user search query", "user123");
suggester.indexer().indexFromQueryLog(queryLog);
```

    assertThat(Doubles.indexOf(ARRAY234, EMPTY)).isEqualTo(0);
    assertThat(Doubles.indexOf(EMPTY, ARRAY234)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY234, ARRAY1)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY1, ARRAY234)).isEqualTo(-1);
    assertThat(Doubles.indexOf(ARRAY1, ARRAY1)).isEqualTo(0);
    assertThat(Doubles.indexOf(ARRAY234, ARRAY234)).isEqualTo(0);

@SuppressWarnings("JUnit4ClassUsedInJUnit3")
public class ListIndexOfTester<E> extends AbstractListIndexOfTester<E> {
  @Override
  protected int find(Object o) {
    return getList().indexOf(o);
  }

  @Override
  protected String getMethodName() {
    return "indexOf";
  }

  @CollectionFeature.Require(absent = REJECTS_DUPLICATES_AT_CREATION)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testIndexOf_duplicate() {

(function(o){var n='';-1!==['width','height','top','right','bottom','left'].indexOf(o)&&Y(t[o])&&(n='px'),e.style[o]=t[o]+n})}function j(e,t){Object.keys(t).forEach(function(o){var n=t[o];!1===n?e.removeAttribute(o):e.setAttribute(o,t[o])})}function q(e,t){var o=e.offsets,n=o.popper,i=o.reference,r=$,p=function(e){return e},s=r(i.width),d=r(n.width),a=-1!==['left','right'].indexOf(e.placement),l=-1!==e.placement.indexOf('-'),f=t?a||l||s%2==d%2?r:Z:p,m=t?r:p;return{left:f(1==s%2&&1==d%2&&!l&&t?n....

                if (userAgent != null) {
                    if (userAgent.indexOf("MSIE") >= 0 || userAgent.indexOf("Trident") >= 0) {
                        uaType = UserAgentType.IE;
                    } else if (userAgent.indexOf("Firefox") >= 0) {
                        uaType = UserAgentType.FIREFOX;
                    } else if (userAgent.indexOf("Chrome") >= 0) {
                        uaType = UserAgentType.CHROME;