    # File lib/rmail/mailbox.rb, line 45
          def parse_mbox(input, line_separator = $/)
            require 'rmail/mailbox/mboxreader'
            retval = []
            RMail::Mailbox::MBoxReader.new(input, line_separator).each_message {
              |reader|
              raw_message = reader.read(nil)
              if block_given?
                yield raw_message
              else
                retval << raw_message
              end
            }
            return block_given? ? nil : retval
          end