code: function isElementAllowed(element) {
    const allowed = ALLOWED_ELEMENTS[element.namespaceURI];
    if (!allowed) {
      return false;
    }
  
    return allowed.indexOf(element.tagName.toLowerCase()) !== -1;
  }
docs: Check if element is allowed in the translation.
  
  This method is used by the sanitizer when the translation markup contains
  an element which is not present in the source code.
  
  @param   {Element} element
  @returns {boolean}
  @private