Defines a Polling Channel Adapter for the
'org.springframework.integration.stream.CharacterStreamReadingMessageSource'
that reads from stdin (System.in).
Configures a Consumer Endpoint for the
'org.springframework.integration.stream.CharacterStreamWritingMessageHandler' that writes to stdout
(System.out) or to stderr (System.err) depending on the element name.
Specifies the order for invocation when this endpoint is connected as a
subscriber to a SubscribableChannel.