How to use the @vtex/api.MetricsAccumulator function in @vtex/api

import {
  IOContext,
  MetricsAccumulator,
  SegmentData,
  ServiceContext,
} from '@vtex/api'

import { Clients } from './clients'
import { IdentityDataSource } from './dataSources/identity'

if (!global.metrics) {
  console.error('No global.metrics at require time')
  global.metrics = new MetricsAccumulator()
}

declare global {
  type Context = ServiceContext

  interface CustomContext {
    cookie: string
    dataSources: StoreGraphQLDataSources
    originalPath: string
    vtex: CustomIOContext
  }

  interface CustomIOContext extends IOContext {
    currentProfile: CurrentProfile
    segment?: SegmentData
    orderFormId?: string