}

    opcode = b0 and B0_MASK_OPCODE
    isFinalFrame = b0 and B0_FLAG_FIN != 0
    isControlFrame = b0 and OPCODE_FLAG_CONTROL != 0

    // Control frames must be final frames (cannot contain continuations).
    if (isControlFrame && !isFinalFrame) {
      throw ProtocolException("Control frames must be final.")
    }

    val reservedFlag1 = b0 and B0_FLAG_RSV1 != 0
    when (opcode) {

    assertFailsWith<IllegalArgumentException> {
      OkHttpClient.Builder()
        .protocols(protocols as List<Protocol>)
    }.also { expected ->
      assertThat(expected.message).isEqualTo("protocols must not contain null")
    }
  }

  @Test fun spdy3IsRemovedFromProtocols() {
    val protocols =
      mutableListOf(
        Protocol.HTTP_1_1,
        Protocol.SPDY_3,
      )
    val client =

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
------------

IntelliJ and Android Studio offer a **Code Cleanup** feature that will automatically update

          } else {
            evictToRecoverBytes(dynamicTableByteCount - maxDynamicTableByteCount)
          }
        }
      }
    }

  /**
   * An HTTP/2 response cannot contain uppercase header characters and must be treated as
   * malformed.
   */
  @Throws(IOException::class)
  fun checkLowercase(name: ByteString): ByteString {
    for (i in 0 until name.size) {