def lookup(id, options={})
      id_type = options.delete(:id_type) || :id
      raise ArgumentError, 'invalid id_type.' unless ID_TYPES.keys.include?(id_type.to_sym)

      warn "#{Kernel.caller.first}: [DEPRECATION] id_type option is deprecated and will be permanently removed in the next major version. Please use ITunes::Lookup methods (amg_artist, amg_album, and upc) instead." unless id_type == :id

      perform_lookup(ID_TYPES[id_type.to_sym], id, options)
    end
def lookup(id, options={})
      id_type = options.delete(:id_type) || :id
      raise ArgumentError, 'invalid id_type.' unless ID_TYPES.keys.include?(id_type.to_sym)

      warn "#{Kernel.caller.first}: [DEPRECATION] id_type option is deprecated and will be permanently removed in the next major version. Please use ITunes::Lookup methods (amg_artist, amg_album, and upc) instead." unless id_type == :id

      perform_lookup(ID_TYPES[id_type.to_sym], id, options)
    end
Performs a lookup request based on iTunes IDs, UPCs/ EANs, and All Music Guide (AMG) IDs
 @param [String] id
 @option options [Symbol] :id_type used to specify the option type being passed, valid types are: id, upc, amg_artist, amg_album
 @raise [ArgumentError] If an invalid id_type is specified in options