noNewExchangesEvent = !candidate.noNewExchanges
            candidate.noNewExchanges = true
            connectionUser.releaseConnectionNoEvents()
          }
          candidate.noNewExchanges || !sameHostAndPort(candidate.route().address.url) -> {
            connectionUser.releaseConnectionNoEvents()
          }
          else -> null
        }
      }

   * detect if followups need to do a full connection-finding process including DNS resolution, and
   * certificate pin checks.
   */
  fun sameHostAndPort(url: HttpUrl): Boolean

  /**
   * A plan holds either an immediately-usable connection, or one that must be connected first.
   * These steps are split so callers can call [connectTcp] on a background thread if attempting