code: def parse_filters(self, branchset_node, uncertainty_type, filters):
          
          if 'applyToSources' in filters:
              filters['applyToSources'] = filters['applyToSources'].split()
          return filters
docs: See superclass' method for description and signature specification.
  
          Converts "applyToSources" filter value by just splitting it to a list.