sublime_text2 command to wrap the current selection with '#{' and '}' when '#' is pressed

gistfile1.json

  { "keys": ["#"], "command": "insert_snippet", "args": {"contents": "#{${0:$SELECTION}}"}, "context":
    [
      { "key": "setting.auto_match_enabled", "operator": "equal", "operand": true },
      { "key": "selection_empty", "operator": "equal", "operand": false, "match_all": true }
    ]
  }