Hi - another possibly dumb question.
If I have for example 10 pairs of fastq files and 1 reference genome that I want to map them to, I have created a channel to pair the fastq files and trim then and feed them into a bwa mapper. How do I ensure that the output channel (containing multiple index files and a dict file) and of an indexing process for the genome does not consumed by the mapping process for the first pair of fastqs.
I've seem example workflows where people have used .first() for a channel but don't really understand why this is necessary. A channel with a single entity doesn't get consumed? I can't find a reference to this in the docs.