val response1 = responses.take()
    assertThat(response1).isEqualTo("")
    assertThat(server.takeRequest().sequenceNumber).isEqualTo(0)

    // Now make the second request which will restrict the first HTTP/2 connection from creating new
    // streams.
    client.newCall(request).enqueue(callback)
    val response2 = responses.take()
    assertThat(response2).isEqualTo("DEF")

          )
        }
      } else if (base != null) {
        this.scheme = base.scheme
      } else {
        val truncated = if (input.length > 6) input.take(6) + "..." else input
        throw IllegalArgumentException(
          "Expected URL scheme 'http' or 'https' but no scheme was found for $truncated",
        )
      }

      // Authority.