code: function isEmpty (node, sourceCode) {
    const start = node.startTag.range[1]
    const end = (node.endTag != null) ? node.endTag.range[0] : node.range[1]
  
    return sourceCode.text.slice(start, end).trim() === ''
  }
docs: Check whether the given element is empty or not.
  This ignores whitespaces, doesn't ignore comments.
  @param {VElement} node The element node to check.
  @param {SourceCode} sourceCode The source code object of the current context.
  @returns {boolean} `true` if the element is empty.