class RuboCop::Cop::RSpec::AroundBlock

def check_for_numblock(block)
  find_arg_usage(block) do |usage|
    return if usage.include?(s(:lvar, :_1))
  end
  add_offense(
    block.children.last,
    message: format(MSG_UNUSED_ARG, arg: :_1)
  )
end