docs: function normalizeContent(content) {
  
    // First, invoke content if it is a function. If it produces an array,
    // that needs to happen before normalization.
    if (typeof content === 'function') {
      content = content();
    }
  
    // Next up, normalize to an array, so one or many items can be normalized,
    // filtered, and returned.
    return (Array.isArray(content) ? content : [content]).map(function (value) {
  
      // First, invoke value if it is a function to produce a new value,
      // which will be subsequently normalized to a Node of some kind.
      if (typeof value === 'function') {
        value = value();
      }
  
      if (isEl(value) || isTextNode(value)) {
        return value;
      }
  
      if (typeof value === 'string' && /\S/.test(value)) {
        return _document2['default'].createTextNode(value);
      }
    }).filter(function (value) {
      return value;
    });
  }