code: function setParents () {
  		var q = async.queue(processFile, 1)
  		q.drain = function () { self.emit('drain') }
  
  		// Process files with no dependency first
  		self.nodeps.forEach( q.push )
  
  		function processFile (item, cb) {
  			debug('dep:', item.id)
  			// Add files with no dependency left to be processed
  			self.deps
  				.forEach(function (file) {
  					if ( file.count > 0 && file.deps.indexOf(item.id) >= 0 ) {
  						item.parents.push(file.id)
  						file.count--
  						debug('file %s -> %d', file.id, file.count)
  						if (file.count === 0) q.push(file)
  					}
  				})
  			cb()
  		}
  	}
docs: Once all files are loaded, set their parents