public static function array_append(&$arr, $path, $value) {
		if(!is_array($path))
			$path = [$path];
		$lastkey = array_pop($path);
		foreach($path as $parent)
			$arr =& $arr[$parent];
		$arr[$lastkey][] = $value;
	}
public static function array_append(&$arr, $path, $value) {
		if(!is_array($path))
			$path = [$path];
		$lastkey = array_pop($path);
		foreach($path as $parent)
			$arr =& $arr[$parent];
		$arr[$lastkey][] = $value;
	}
public static function array_append ( & $ arr , $ path , $ value ) { if ( ! is_array ( $ path ) ) $ path = [ $ path ] ; $ lastkey = array_pop ( $ path ) ; foreach ( $ path as $ parent ) $ arr = & $ arr [ $ parent ] ; $ arr [ $ lastkey ] [ ] = $ value ; }
Add element in array.
@param  array        $arr
@param  string|array $path  list of nested keys.
@param  mixed        $value
@api
Add element in array .