#### Credentials.basic()

The username and password parameters to `Credentials.basic()` are now non-null strings. In OkHttp
3.x, null would yield a username or password of "null".

#### HttpUrl.queryParameterValues()

The return type of `HttpUrl.queryParameterValues()` is `List<String?>`. Lists that may contain null
are uncommon and Kotlin callers may have incorrectly assigned the result to `List<String>`.


Code Cleanup
------------

    assertThat(url.queryParameterValue(1)).isNull()
    assertThat(url.queryParameterValue(2)).isNull()
    assertThat(url.queryParameterValues("foo")).isEqualTo(listOf(null as String?))
    assertThat(url.queryParameterValues("bar")).isEqualTo(listOf(null as String?))
    assertThat(url.queryParameterValues("baz")).isEqualTo(listOf(null as String?))
  }

  @Test
  fun queryParametersWithEmptyValues() {

    val querySize: Int = httpUrl.querySize
    val queryParameter: String? = httpUrl.queryParameter("")
    val queryParameterNames: Set<String> = httpUrl.queryParameterNames
    val queryParameterValues: List<String?> = httpUrl.queryParameterValues("")
    val queryParameterName: String = httpUrl.queryParameterName(0)
    val queryParameterValue: String? = httpUrl.queryParameterValue(0)
    val encodedFragment: String? = httpUrl.encodedFragment

   * URL. For example this returns `["banana"]` for `queryParameterValue("b")` on
   * `http://host/?a=apple&b=banana`.
   *
   * | URL                               | `queryParameterValues("a")` | `queryParameterValues("b")` |
   * | :-------------------------------- | :-------------------------- | :-------------------------- |
   * | `http://host/`                    | `[]`                        | `[]`                        |

	public final fun queryParameterName (I)Ljava/lang/String;
	public final fun queryParameterNames ()Ljava/util/Set;
	public final fun queryParameterValue (I)Ljava/lang/String;
	public final fun queryParameterValues (Ljava/lang/String;)Ljava/util/List;
	public final fun querySize ()I
	public final fun redact ()Ljava/lang/String;
	public final fun resolve (Ljava/lang/String;)Lokhttp3/HttpUrl;

	public final fun queryParameterName (I)Ljava/lang/String;
	public final fun queryParameterNames ()Ljava/util/Set;
	public final fun queryParameterValue (I)Ljava/lang/String;
	public final fun queryParameterValues (Ljava/lang/String;)Ljava/util/List;
	public final fun querySize ()I
	public final fun redact ()Ljava/lang/String;
	public final fun resolve (Ljava/lang/String;)Lokhttp3/HttpUrl;