A FunctionCallResponse packet is sent by the server after the execution of a function (i.e. a FunctionCall packet sent by the client).
String packetType: "FunctionCallResponse"
byte[] bytes: the raw bytes forming the payload of this packet. The meaning of the payload depends on the function's return type.
array getJSBytes() : gets the bytes forming the payload of this packet, in a JavaScript-friendly format. The array should not be changed unless setJSBytes is called.
void setJSBytes(array) : sets the payload bytes for this packet.