Implementations return true if they can continue processing - e.g. there
is a data source that is not yet exhausted. Exceptions are not necessarily
fatal - processing might continue depending on the Exception type and the
implementation of the caller.
context - the current context passed in by the caller.
an RepeatStatus which is continuable if there is (or may
be) more data to process.
java.lang.Exception - if there is a problem with the processing.