code: void setVersion(ProtocolVersion protocolVersion) {
          this.protocolVersion = protocolVersion;
          setVersionSE(protocolVersion);
  
          output.r.setVersion(protocolVersion);
      }
docs: Set the active protocol version and propagate it to the SSLSocket
  and our handshake streams. Called from ClientHandshaker
  and ServerHandshaker with the negotiated protocol version.