resolve_row_separator

# File lib/csv/parser.rb, line 532
    def resolve_row_separator(separator)
      if separator == :auto
        cr = "\r".encode(@encoding)
        lf = "\n".encode(@encoding)
        if @input.is_a?(StringIO)
          separator = detect_row_separator(@input.string, cr, lf)
        elsif @input.respond_to?(:gets)
          if @input.is_a?(File)
            chunk_size = 32 * 1024
          else
            chunk_size = 1024
          end
          begin
            while separator == :auto
              #
              # if we run out of data, it's probably a single line
              # (ensure will set default value)
              #
              break unless sample = @input.gets(nil, chunk_size)

              # extend sample if we're unsure of the line ending
              if sample.end_with?(cr)
                sample << (@input.gets(nil, 1) || "")
              end

              @samples << sample

              separator = detect_row_separator(sample, cr, lf)
            end
          rescue IOError
            # do nothing:  ensure will set default
          end
        end
        separator = $INPUT_RECORD_SEPARATOR if separator == :auto
      end
      separator.to_s.encode(@encoding)
    end