code: @Deprecated
    public final OkHttpChannelBuilder negotiationType(io.grpc.okhttp.NegotiationType type) {
      Preconditions.checkNotNull(type, "type");
      switch (type) {
        case TLS:
          negotiationType = NegotiationType.TLS;
          break;
        case PLAINTEXT:
          negotiationType = NegotiationType.PLAINTEXT;
          break;
        default:
          throw new AssertionError("Unknown negotiation type: " + type);
      }
      return this;
    }
docs: Sets the negotiation type for the HTTP/2 connection.
  
  <p>If TLS is enabled a default {@link SSLSocketFactory} is created using the best
  {@link java.security.Provider} available and is NOT based on
  {@link SSLSocketFactory#getDefault}. To more precisely control the TLS configuration call
  {@link #sslSocketFactory} to override the socket factory used.
  
  <p>Default: <code>TLS</code>
  
  @deprecated use {@link #usePlaintext()} or {@link #useTransportSecurity()} instead.