src/extensions/group-by-v2/bootstrap-table-group-by.js
function (str) {
  const args = arguments
  let flag = true
  let i = 1

  str = str.replace(/%s/g, () => {
    const arg = args[i++]

    if (typeof arg === 'undefined') {
      flag = false
      return ''
    }
    return arg
  })
  return flag ? str : ''
}
function (str) {
  const args = arguments
  let flag = true
  let i = 1

  str = str.replace(/%s/g, () => {
    const arg = args[i++]

    if (typeof arg === 'undefined') {
      flag = false
      return ''
    }
    return arg
  })
  return flag ? str : ''
}
it only does '%s', and return '' when arguments are undefined