fn back_process(&mut self, node: &Value) -> &Vec<Option<Value>> {
    let empty_arr = vec![];
    let id = &node["id"].as_u64().expect("Invalid node ID") as &u64;
    let nodes = self.nodes;

    if self.nodes_output.contains_key(id) == true {
      return &self.nodes_output[id];
    };

    let mut input_data: Vec<Vec<&Option<Value>>> = [].to_vec();
    let inputs = &node["inputs"].as_array().unwrap_or(&empty_arr);

    for i in 0..inputs.len() {
      let mut out_data: Vec<&Option<Value>> = [].to_vec();
      let input = &inputs[i];
      let connections = input["connections"].as_array().unwrap_or(&empty_arr);


      for i2 in 0..connections.len() {
        let c = &connections[i2];
        let nid = c["node"].as_u64().expect("Invalid connection node ID") as u64;
        let nn = &nodes.unwrap()[nid as usize]; // TODO rename
        let out = self.back_process(&nn);
        let out_index = c["output"]
          .as_u64()
          .expect("Invalid connection output index") as u64;
        let val = &out[out_index as usize];
        //val
        out_data.push(val);
      };

    }


    return self.nodes_output.get(&id).unwrap();
  }