something is working

node_modules/mongoose/lib/helpers/schema/handleIdOption.js

@@ -0,0 +1,20 @@
+'use strict';
+
+const addAutoId = require('./addAutoId');
+
+module.exports = function handleIdOption(schema, options) {
+  if (options == null || options._id == null) {
+    return schema;
+  }
+
+  schema = schema.clone();
+  if (!options._id) {
+    schema.remove('_id');
+    schema.options._id = false;
+  } else if (!schema.paths['_id']) {
+    addAutoId(schema);
+    schema.options._id = true;
+  }
+
+  return schema;
+};