--- /dev/null
+var forEach = require('../array/forEach');
+var slice = require('../array/slice');
+var forOwn = require('./forOwn');
+
+ /**
+ * Copy missing properties in the obj from the defaults.
+ */
+ function fillIn(obj, var_defaults){
+ forEach(slice(arguments, 1), function(base){
+ forOwn(base, function(val, key){
+ if (obj[key] == null) {
+ obj[key] = val;
+ }
+ });
+ });
+ return obj;
+ }
+
+ module.exports = fillIn;
+
+