title: What should be the type of a field in schema if "any" cannot be used in Nest.js?
body: <p>I'm working in Nest.js using Mongoose. While creating schema, I have a field extra_options which can store any type of value (array, object, string etc). Keeping its type as &quot;any&quot; does not work. What should be the correct type? Here is a fragment of the code.</p>
  <pre><code>@Schema({
      collection: 'xyz',
      timestamps: {
          updatedAt: 'updated_at',
          createdAt: 'created_at'
      },
  })
  export class xyz {
      @Prop({default: true})
      active: boolean;
  
      @Prop()
      extra_options: any;
  
      @Prop({required: true})
      created_by: string;
  }
  </code></pre>