public long tlsHandshakeStartTimeMicros() {
        return tlsHandshakeStartTimeMicros;
    }
Returns the time when the client started to TLS handshake, in microseconds since the epoch.

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