are called instead of `requestBodyEnd()` and `responseBodyEnd()` in some failure situations.
    They may also be fired in cases where no event was published previously. In this release we did
    an internal rewrite of our event code to fix problems where events were lost or unbalanced.

 *  Fix: Don't leak a connection when a call is canceled immediately preceding the `onFailure()`
    callback.

   * (preferring constructors with at least one {@code String}, then preferring constructors with at
   * least one {@code Throwable}) and calling the constructor via reflection. If the exception did
   * not already have a cause, one is set by calling {@link Throwable#initCause(Throwable)} on it.
   * If no such constructor exists, an {@code IllegalArgumentException} is thrown.
   *