Refactoring day1

node_modules/mongodb/lib/write_concern.js

@@ -1,7 +1,5 @@
 'use strict';
 
-const kWriteConcernKeys = new Set(['w', 'wtimeout', 'j', 'fsync']);
-
 /**
  * The **WriteConcern** class is a class that represents a MongoDB WriteConcern.
  * @class
@@ -53,14 +51,6 @@ class WriteConcern {
     }
 
     if (options.writeConcern) {
-      if (typeof options.writeConcern === 'string') {
-        return new WriteConcern(options.writeConcern);
-      }
-
-      if (!Object.keys(options.writeConcern).some(key => kWriteConcernKeys.has(key))) {
-        return;
-      }
-
       return new WriteConcern(
         options.writeConcern.w,
         options.writeConcern.wtimeout,