title: How to open angular2-multiselect-dropdown on clicking external button
body: <p>I was trying to access angular2-multiselect-dropdown vesrion 4.6.3 .</p>
  <p>Here, I wanted to open the dropdown on external button click.</p>
  <pre><code>&lt;angular2-multiselect 
    [data]=&quot;dropdownList&quot; 
    [(ngModel)]=&quot;selectedItems&quot;
    [settings]=&quot;dropdownSettings&quot; 
    #dropdownRef&gt;
  &lt;/angular2-multiselect&gt;
          
  &lt;button (click)=&quot;openDropdown&quot; &gt;
    Click Here to Open Dropdown
  &lt;/button&gt;
      
  @ViewChild('dropdownRef',{static:false}) dropdownRef: AngularMultiSelect;
              
  openDropdown(){
    // Open Dropdown Method not working
    this.dropdownRef.openDropdown();
   }
  
  </code></pre>
  <p>Reproduce link : <a href="https://stackblitz.com/edit/r7-angular2-multislect-8as6pk?file=src%2Fapp%2Fapp.component.html" rel="nofollow noreferrer">https://stackblitz.com/edit/r7-angular2-multislect-8as6pk?file=src%2Fapp%2Fapp.component.html</a></p>