code: function makeEntry (entry: any, entries: Array<string> = []): Object {
    if (typeof entry === 'string') {
      entry = [entry]
    }
    if (Array.isArray(entry)) {
      entry = { main: entry }
    }
    return Object.keys(entry)
      .reduce((acc, x) => {
        const v = entry[x]
        return {
          ...acc,
          [x]: [
            ...entries,
            ...(Array.isArray(v) ? v : [v])
          ]
        }
      }, {})
  }
docs: /* @flow