code: function(filter, index, list) {
          // Shortcuts
          if (filter === 'combine') {
              list[index] = self.filters.combine;
              return;
          }
  
          // Solfege URI
          if (typeof filter === 'string' && self.application.isSolfegeUri(filter)) {
              list[index] = self.application.resolveSolfegeUri(filter, self);
          }
      }
docs: The function used by forEach method