@shift_map(m:map, n:numeric)

build a new map containing the entries of m that have a integer key with n added. For example:

       $m := MAP{ (1, 1), ("a", 1), (1.0, 1)
                  (2, 2), ("b", 2), (2.0, 2) }
       print (@shift_map($m, 11))
displays MAP{ (12, 1), (13, 2) }.

See also Map (aka dictionnary) @add_pair    @clear    [@clone]    @count    @domain    @find    @gshift_map    @insert    @is_defined    @is_function    @is_map    @listify    @make_duration_map    @make_label_bpm    @make_label_duration    @make_label_pitches    @make_label_pos    @make_score_map    @map    @map_compose    @map_concat    @map_history    @map_history_date    @map_history_rdate    @map_normalize    @map_reverse    @mapval    @max_key    @max_val    @member    @merge    @min_key    @min_val    @occurs    @range    @remove    @select_map    @shift_map