code: function addFlattened(array, item) {
    if (item === null || typeof item !== 'object') {
      const child =
        item === undefined || item === null || item === true || item === false
          ? ''
          : '' + item
  
      const arrayLength = array.length
  
      if (arrayLength > 0 && typeof array[arrayLength - 1] === 'string') {
        array[arrayLength - 1] += child
      } else {
        array.push(child)
      }
    } else if (Array.isArray(item)) {
      for (let i = 0; i < item.length; ++i) {
        addFlattened(array, item[i])
      }
    } else if (item[Symbol.iterator]) {
      for (const x of item) {
        addFlattened(array, x)
      }
    } else {
      array.push(item)
    }
  }
docs: --- locals -------------------------------------------------------