@SuppressWarnings("unchecked")
  public <T> T invoke(String methodName, Object argument, Class<T> returnType) throws Throwable {
    return (T) invoke(methodName, argument, (Type) returnType);
  }
Invoke a JSON-RPC method synchronously.

<p>This method should not be used directly, prefer using {@link #newProxy(Class)} to create a
strongly-typed dynamic proxy for a Java interface instead.

@throws IOException if serializing the request payload or deserializing the response payload
    fails
@throws Throwable if the response is a serialized exception from the server
json-rpc-lambda-client/src/main/java/com/amazonaws/blox/jsonrpc/JsonRpcLambdaClient.java