code: function(next) {
            Q.all(sources.map(function(src) {
              return Q.nfcall(fs.stat, src)
              .then(function(stat) {
                statSources[src] = stat;
              });
            }))
            .then(function() { next(); })
            .fail(function(err) {next(err);});
          }
docs: All sources stats