code: function( callback ) {
  
          var scope = this;
  
          if( ! scope.shots.length ) {
  
              callback && callback( new Error( "Camera has no last shot" ) );
  
          }
  
          scope.getBase64( scope.shots.length - 1, callback );
  
      }
docs: Get last shot taken base 64 string
  
  @method getLastShot64
  
  @param {Function} callback