Dr. Frey wanted to know what happens when you have a fixed mod in the same spot as a uniprot mod. This PR adds a unit test that evaluates that functionality. Here we have an xml database with acetylation on serine at position 2. I created a fixed mod (hydroxylation of serine) and passed that into the protein.digest function. Digestion of that protein yields both forms showing that the uniprot mod replaces the fixed mod when necessary and you get peptides with both acetyl and oh.
Dr. Frey wanted to know what happens when you have a fixed mod in the same spot as a uniprot mod. This PR adds a unit test that evaluates that functionality. Here we have an xml database with acetylation on serine at position 2. I created a fixed mod (hydroxylation of serine) and passed that into the protein.digest function. Digestion of that protein yields both forms showing that the uniprot mod replaces the fixed mod when necessary and you get peptides with both acetyl and oh.