private ConscryptSession provideHandshakeSession() {
        synchronized (ssl) {
            return state >= STATE_HANDSHAKE_STARTED && state < STATE_READY ? activeSession
                : SSLNullSession.getNullSession();
        }
    }
Method acts as described in spec for superclass.
@see java.io.OutputStream#write(byte[],int,int)
common/src/main/java/org/conscrypt/ConscryptFileDescriptorSocket.java