Merge pull request #15232 from Automattic/vkarpov15/gh-15208

docs(document): clarify that toObject() returns a POJO that may contain non-POJO values

lib/document.js

@@ -4069,7 +4069,7 @@ Document.prototype.$__toObjectShallow = function $__toObjectShallow() {
  * @param {Boolean} [options.flattenMaps=false] if true, convert Maps to POJOs. Useful if you want to `JSON.stringify()` the result of `toObject()`.
  * @param {Boolean} [options.flattenObjectIds=false] if true, convert any ObjectIds in the result to 24 character hex strings.
  * @param {Boolean} [options.useProjection=false] - If true, omits fields that are excluded in this document's projection. Unless you specified a projection, this will omit any field that has `select: false` in the schema.
- * @return {Object} js object (not a POJO)
+ * @return {Object} document as a plain old JavaScript object (POJO). This object may contain ObjectIds, Maps, Dates, mongodb.Binary, Buffers, and other non-POJO values.
  * @see mongodb.Binary https://mongodb.github.io/node-mongodb-native/4.9/classes/Binary.html
  * @api public
  * @memberOf Document