could use new flow control capacity before acknowledging it, causing strict HTTP/2 servers to
    fail the call.


## Version 4.1.1

_2019-09-05_

 *  Fix: Don't drop repeated headers when validating cached responses. In our Kotlin upgrade we
    introduced a regression where we iterated the number of unique header names rather than then

    assertThat(pool.closeConnections(150L)).isEqualTo(0)
    assertThat(pool.connectionCount()).isEqualTo(0)
    assertThat(c1.socket().isClosed).isTrue()

    // Running again, the pool reports that no further runs are necessary.
    assertThat(pool.closeConnections(150L)).isEqualTo(-1)
    assertThat(pool.connectionCount()).isEqualTo(0)
    assertThat(c1.socket().isClosed).isTrue()
  }