# File lib/unified_ruby.rb, line 40
  def rewrite_block_pass exp
    if exp.size == 3 then
      _, block, recv = exp
      case recv.first
      when :super then
        recv << s(:block_pass, block)
        exp = recv
      when :call then
        recv.last << s(:block_pass, block)
        exp = recv
      else
        raise "huh?: #{recv.inspect}"
      end
    end

    exp
  end