title: Access to Angular Formly Material Datepicker
body: <p>I want to access the formly datepicker to make it close after selecting the year.
  But Im not able to access the datepicer object. Can please anybody help? Thank you!</p>
  <pre><code>  fieldsOfMyForm: FormlyFieldConfig[] = [
      {
        key: 'form',
        type: 'repeat',
        templateOptions: {
          addText: 'my form',
  
        },
        fieldArray: { fieldGroup: [ 
           {
              key: 'myyear',
              type: 'datepicker',
              templateOptions: {  
                 datepickerOptions: { 
                      yearSelected: (( field: any, event: Moment) =&gt; { 
                         // here is the part where I want to calls something like datepicker.close(); 
                      }
                  }
               }
         ] }
  </code></pre>