@Override
    public final void setWantClientAuth(boolean want) {
        sslParameters.setWantClientAuth(want);
    }
Sets the {@link PrivateKey} to be used for TLS Channel ID by this client socket.

<p>This method needs to be invoked before the handshake starts.

@param privateKey private key (enables TLS Channel ID) or {@code null} for no key (disables
       TLS Channel ID). The private key must be an Elliptic Curve (EC) key based on the NIST
       P-256 curve (aka SECG secp256r1 or ANSI X9.62 prime256v1).

@throws IllegalStateException if this is a server socket or if the handshake has already
        started.
common/src/main/java/org/conscrypt/ConscryptFileDescriptorSocket.java