code: function (partialString) {
      var edgeQuotesMatcher = /^["']|["']$/g;
      var partialIDWithQuotes = partialString.replace(this.findPartialsRE, '$1');
      var partialID = partialIDWithQuotes.replace(edgeQuotesMatcher, '');
  
      return partialID;
    }
docs: given a pattern, and a partial string, tease out the "pattern key" and return it.