code: function toYUICoverage(coverage) {
      var ret = {};
  
      addDerivedInfo(coverage);
  
      Object.keys(coverage).forEach(function (k) {
        var fileCoverage = coverage[k],
          lines = fileCoverage.l,
          functions = fileCoverage.f,
          fnMap = fileCoverage.fnMap,
          o;
  
        o = ret[k] = {
          lines: {},
          calledLines: 0,
          coveredLines: 0,
          functions: {},
          calledFunctions: 0,
          coveredFunctions: 0
        };
        Object.keys(lines).forEach(function (k) {
          o.lines[k] = lines[k];
          o.coveredLines += 1;
          if (lines[k] > 0) {
            o.calledLines += 1;
          }
        });
        Object.keys(functions).forEach(function (k) {
          var name = fnMap[k].name + ':' + fnMap[k].line;
          o.functions[name] = functions[k];
          o.coveredFunctions += 1;
          if (functions[k] > 0) {
            o.calledFunctions += 1;
          }
        });
      });
      return ret;
    }
docs: makes the coverage object generated by this library yuitest_coverage compatible.
  Note that this transformation is lossy since the returned object will not have
  statement and branch coverage.
  
  @method toYUICoverage
  @static
  @param {Object} coverage The `istanbul` coverage object
  @return {Object} a coverage object in `yuitest_coverage` format.