send_body_io

# File lib/webrick/httpresponse.rb, line 255
    def send_body_io(socket)
      begin
        if @request_method == "HEAD"
          # do nothing
        elsif chunked?
          while buf = @body.read(@buffer_size)
            next if buf.empty?
            data = ""
            data << format("%x", buf.bytesize) << CRLF
            data << buf << CRLF
            _write_data(socket, data)
            @sent_size += buf.bytesize
          end
          _write_data(socket, "0#{CRLF}#{CRLF}")
        else
          size = @header['content-length'].to_i
          _send_file(socket, @body, 0, size)
          @sent_size = size
        end
      ensure
        @body.close
      end
    end