code: function _isHex(value) {
    var hexRegex = /^[0-9a-f]{2,}$/i
    var isHex = hexRegex.test(value) && !(value.length % 2)
    return isHex
  }
docs: Checks if value is a hexadecimal string
  
  @param {string} value - The value to check
  @returns {bool} true if value is a hexadecimal string, otherwise false