A processor that applies a list of child processors to messages of a batch as
though they were each a batch of one message (similar to the
for_each processor), but where each message is
processed in parallel.
parallel:cap: 0processors: 
cap, if greater than zero, caps the maximum number of
parallel processing threads.
The functionality of this processor depends on being applied across messages that are batched. You can find out more about batching in this doc.
number The maximum number of messages to have processing at a given time.
array A list of child processors to apply.