init_with

# File actionpack/lib/action_controller/metal/strong_parameters.rb, line 935
    def init_with(coder) # :nodoc:
      case coder.tag
      when "!ruby/hash:ActionController::Parameters"
        # YAML 2.0.8's format where hash instance variables weren't stored.
        @parameters = coder.map.with_indifferent_access
        @permitted  = false
      when "!ruby/hash-with-ivars:ActionController::Parameters"
        # YAML 2.0.9's Hash subclass format where keys and values
        # were stored under an elements hash and `permitted` within an ivars hash.
        @parameters = coder.map["elements"].with_indifferent_access
        @permitted  = coder.map["ivars"][:@permitted]
      when "!ruby/object:ActionController::Parameters"
        # YAML's Object format. Only needed because of the format
        # backwards compatibility above, otherwise equivalent to YAML's initialization.
        @parameters, @permitted = coder.map["parameters"], coder.map["permitted"]
      end
    end