lib/operations/collection_ops.js
function updateOne(coll, filter, update, options, callback) {
  // Set single document update
  options.multi = false;
  // Execute update
  updateDocuments(coll, filter, update, options, (err, r) => updateCallback(err, r, callback));
}
function updateOne(coll, filter, update, options, callback) {
  // Set single document update
  options.multi = false;
  // Execute update
  updateDocuments(coll, filter, update, options, (err, r) => updateCallback(err, r, callback));
}
function updateOne ( coll , filter , update , options , callback ) { // Set single document update options . multi = false ; // Execute update updateDocuments ( coll , filter , update , options , ( err , r ) => updateCallback ( err , r , callback ) ) ; }
Update a single document in the collection.

@method
@param {Collection} a Collection instance.
@param {object} filter The Filter used to select the document to update
@param {object} update The update operations to be applied to the document
@param {object} [options] Optional settings. See Collection.prototype.updateOne for a list of options.
@param {Collection~updateWriteOpCallback} [callback] The command result callback
Update a single document in the collection .