function(handle) {
        if (!isValidID(handle)) return null;

        var i, j, instance;
        for (i = 0, j = instances.length; i < j; i++) {
          instance = instances[i];
          if (instance.$$mdHandle === handle) {
            return instance;
          }
        }
        return null;
      }
function(handle) {
        if (!isValidID(handle)) return null;

        var i, j, instance;
        for (i = 0, j = instances.length; i < j; i++) {
          instance = instances[i];
          if (instance.$$mdHandle === handle) {
            return instance;
          }
        }
        return null;
      }
function ( handle ) { if ( ! isValidID ( handle ) ) return null ; var i , j , instance ; for ( i = 0 , j = instances . length ; i < j ; i ++ ) { instance = instances [ i ] ; if ( instance . $$mdHandle === handle ) { return instance ; } } return null ; }
Get a registered instance.
@param handle the String handle to look up for a registered instance.
Get a registered instance .
Returns the instance of the given handle