+# swap [container] [with] id <window>
+# swap [container] [with] con_id <con_id>
+# swap [container] [with] mark <mark>
+state SWAP:
+ 'container'
+ ->
+ 'with'
+ ->
+ mode = 'id', 'con_id', 'mark'
+ -> SWAP_ARGUMENT
+
+state SWAP_ARGUMENT:
+ arg = string
+ -> call cmd_swap($mode, $arg)
+