How to use the effector.launch function in effector

],
    parent: effects,
  })
  const onEnd = createNode({
    node: [
      step.run({
        fn() {
          fxCount -= 1
          completeInitPhase()
        },
      }),
    ],
    parent: finalizers,
  })
  if (start) {
    launch(find(start), ctx)
  }
  isSyncComplete = true
  completeInitPhase()
  return defer.req
}
function flatGraph(unit) {

function universalLaunch(unit, payload) {
  if (stack.length > 0) {
    invoke(unit, payload)
  } else {
    launch(unit, payload)
  }
}
export function fork(domain, {values = {}} = {}) {

export function invoke(unit, payload) {
  if (stack.length === 0) {
    throw Error('invoke cannot be called outside of forked .watch')
  }
  launch(stack[stack.length - 1](unit), payload)
}

? params => {
      const req = new Defer()
      launch(unit, {params, req})
      return req.req
    }
    : payload => {

return payload => {
    launch(result, payload)
  }
}

: payload => {
      launch(unit, payload)
      return payload
    }
  return React.useCallback(result, [scope, event])