public long pendingAcquisitionStartTimeMicros() {
        return pendingAcquisitionStartTimeMicros;
    }
Returns the time when the client started to wait for the completion of an existing connection attempt,
in microseconds since the epoch.

@return the start time, or {@code -1} if there was no action to get a pending connection.
core/src/main/java/com/linecorp/armeria/common/logging/ClientConnectionTimings.java