Non-linear pipelines

[Augusto Ribeiro Silva]

Hi,

I couldn’t find any example on the documentation about the definition of 
non-linear pipelines (not sure this is the right name to call it). 
What I want to do is something like this:

Pipeline: A -> (B or C) -> D

So the step A supports two file formats, then depending on the file format a 
normalisation step B or C should be performed. Then D should be performed for 
the result of B and C. How would I go about defining such pipeline or if it is 
even possible to do it.

Thanks for the help in advance.

Best regards,
Augusto