npm and error messages

node_modules/deep-equal/lib/is_arguments.js

@@ -0,0 +1,20 @@
+var supportsArgumentsClass = (function(){
+  return Object.prototype.toString.call(arguments)
+})() == '[object Arguments]';
+
+exports = module.exports = supportsArgumentsClass ? supported : unsupported;
+
+exports.supported = supported;
+function supported(object) {
+  return Object.prototype.toString.call(object) == '[object Arguments]';
+};
+
+exports.unsupported = unsupported;
+function unsupported(object){
+  return object &&
+    typeof object == 'object' &&
+    typeof object.length == 'number' &&
+    Object.prototype.hasOwnProperty.call(object, 'callee') &&
+    !Object.prototype.propertyIsEnumerable.call(object, 'callee') ||
+    false;
+};

node_modules/deep-equal/lib/keys.js

@@ -0,0 +1,9 @@
+exports = module.exports = typeof Object.keys === 'function'
+  ? Object.keys : shim;
+
+exports.shim = shim;
+function shim (obj) {
+  var keys = [];
+  for (var key in obj) keys.push(key);
+  return keys;
+}