class RuboCop::Cop::Style::OptionalArguments

def argument_positions(arguments)
  optarg_positions = []
  arg_positions = []
  arguments.each_with_index do |argument, index|
    optarg_positions << index if argument.optarg_type?
    arg_positions << index if argument.arg_type?
  end
  [optarg_positions, arg_positions]
end