data FunctionAddress:
  peer_id: string
  service_id: string

func get_service_id_no_try(node: string, services: []FunctionAddress) -> string:
  res: *string
  for service <- services:
    if service.peer_id == node:
      res <<- service.service_id
  <- res[0]

func get_service_id_try(node: string, services: []FunctionAddress) -> string:
  res: *string
  for service <- services try:
    if service.peer_id == node:
      res <<- service.service_id
  <- res[0]

func get_service_id_par(node: string, services: []FunctionAddress) -> string:
  res: *string
  for service <- services par:
    if service.peer_id == node:
      res <<- service.service_id
  <- res[0]