showWarningsForAttributes = (el, allowedAttributes) => {
  Array.from(el.attributes).forEach((attribute) => {
    if (allowedAttributes.indexOf(attribute.name) === -1) {
      warn([
        `Unrecognized attribute "${attribute.name}" on <${el.tagName.toLowerCase()}>.`,
        `${
          allowedAttributes.length
            ? `Allowed attributes are: ${allowedAttributes.join(', ')}`
            : 'To set the value, use HTML within the element.'
        }`,
      ])
    }
  })
}
@param {HTMLElement} el
@param {string[]} allowedAttributes