code: function(other) {
          var comps = ["a", "b", "c", "d"],
              i, len;
  
          for (i=0, len=comps.length; i < len; i++) {
              if (this[comps[i]] < other[comps[i]]) {
                  return -1;
              } else if (this[comps[i]] > other[comps[i]]) {
                  return 1;
              }
          }
  
          return 0;
      }
docs: Compare this specificity to another.
  @param {Specificity} other The other specificity to compare to.
  @return {int} -1 if the other specificity is larger, 1 if smaller, 0 if equal.
  @method compare