function createDom (el = 'div', tpl = '', attrs = {}, cname = '') {
  const dom = document.createElement(el)
  dom.className = cname
  dom.innerHTML = tpl
  Object.keys(attrs).forEach(item => {
    const key = item
    const value = attrs[item]
    if (el === 'video' || el === 'audio' || el === 'live-video') {
      if (value) {
        dom.setAttribute(key, value)
      }
    } else {
      dom.setAttribute(key, value)
    }
  })
  return dom
}
@param { string } el
@param { string } [tpl=]
@param { {[propName: string]: any }} [attrs={}]
@param { string } [cname='']
@returns { HTMLElement | null }