code: function rule (name, args) {
    return { name, args: !args ? [] : (Array.isArray(args) ? args : [args]) }
  }
docs: /*
  indicative
  
  (c) Harminder Virk <virk@adonisjs.com>
  
  For the full copyright and license information, please view the LICENSE
  file that was distributed with this source code.
   
  Since haye pipe expression cannot allow all the keywords, this
  method helps in defining rules in a raw format.
  
  ## Note
  When using `rule` method, you cannot make use of string expression
  for that field. However, you can mix both for different fields.
  
  @param  {String}              name
  @param  {Array|String|Number} args
  @return {Object}
  
  @example
  {
  username: [
  rule('required'),
  rule('alpha')
  ],
  email: 'email'
  }