code: function _getQueryLength (length) {
    length = /(-?\d*\.?\d+)(ch|em|ex|px|rem)/.exec(length)
  
    if (length === null) {
      return maxValue
    }
  
    let number = length[1]
    const unit = length[2]
  
    switch (unit) {
      case 'ch':
        number = parseFloat(number) * 8.8984375
        break
  
      case 'em':
      case 'rem':
        number = parseFloat(number) * 16
        break
  
      case 'ex':
        number = parseFloat(number) * 8.296875
        break
  
      case 'px':
        number = parseFloat(number)
        break
    }
  
    return +number
  }
docs: Obtain the length of the media request in pixels.
  Copy from original source `function inspectLength (length)`
  {@link https://github.com/hail2u/node-css-mqpacker/blob/master/index.js#L58}
  @private
  @param {string} length
  @return {number}