allowDuplicates(false) not working with SimpleCursorAdapter #39

public class ContactCompleteTextView extends TokenCompleteTextView {

    public ContactCompleteTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        allowDuplicates(false);
        setTokenClickStyle(TokenCompleteTextView.TokenClickStyle.Delete);
    }

    @Override
    protected View getViewForObject(Object object) {
        if (object != null) {
            Cursor c = (Cursor) object;

            LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(
                    Context.LAYOUT_INFLATER_SERVICE);
            LinearLayout view = (LinearLayout) inflater.inflate(R.layout.contact_token,
                    (ViewGroup) ContactCompleteTextView.this.getParent(), false);

            String name = c.getString(c.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
            ((TextView) view.findViewById(R.id.name)).setText(name);
            return view;
        }
        return null;
    }

    @Override
    protected Object defaultObject(String completionText) {
        // Avoid creation
        return null;
      }
  }

        final String contactIdCol = ContactsContract.CommonDataKinds.Phone._ID;
        final String contactNameCol = ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME;
        final String contactPhoneCol = ContactsContract.CommonDataKinds.Phone.NUMBER;

        int[] displayViews = new int[] { android.R.id.text1, android.R.id.text2 };
        String[] displayCols = new String[] {
                contactNameCol,
                contactPhoneCol
        };

        final String[] queryProjection = new String[] {
                contactIdCol,
                contactNameCol,
                contactPhoneCol
        };

        SimpleCursorAdapter adapter = new SimpleCursorAdapter(this,
                android.R.layout.simple_list_item_2, null, displayCols, displayViews, 0);

        adapter.setFilterQueryProvider(new FilterQueryProvider() {
            public Cursor runQuery(CharSequence constraint) {
                return getContentResolver().query(
                        ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                        queryProjection,
                        contactNameCol + " LIKE '%" + constraint + "%'",
                        null, null);
            }
        });

        mTtvContacts.setAdapter(adapter);