src/modules/Dropdown/DropdownMenu.js
function DropdownMenu(props) {
  const { children, className, content, direction, open, scrolling } = props
  const classes = cx(
    direction,
    useKeyOnly(open, 'visible'),
    useKeyOnly(scrolling, 'scrolling'),
    'menu transition',
    className,
  )
  const rest = getUnhandledProps(DropdownMenu, props)
  const ElementType = getElementType(DropdownMenu, props)

  return (
    <ElementType {...rest} className={classes}>
      {childrenUtils.isNil(children) ? content : children}
    </ElementType>
  )
}
function DropdownMenu(props) {
  const { children, className, content, direction, open, scrolling } = props
  const classes = cx(
    direction,
    useKeyOnly(open, 'visible'),
    useKeyOnly(scrolling, 'scrolling'),
    'menu transition',
    className,
  )
  const rest = getUnhandledProps(DropdownMenu, props)
  const ElementType = getElementType(DropdownMenu, props)

  return (
    <ElementType {...rest} className={classes}>
      {childrenUtils.isNil(children) ? content : children}
    </ElementType>
  )
}
A dropdown menu can contain a menu.