  (1:0-6) before;                 <--    (3:2-8)   before;
          ^^^^^^                                   ^^^^^^

  (1:6-7) fore;                   <--    (3:8-9) fore;
              ^                                      ^

  (2:0-6) using x =               <--    (4:2-6)   var x = 
          ^^^^^^                                   ^^^^

  (2:6-7) ing x = f               <--    (4:6-7) var x = _
              ^                                      ^

 (2:7-10) ng x = fn()             <--   (4:7-10) ar x = _usi
              ^^^                                    ^^^

 (2:7-10) ng x = fn()             <--  (4:10-19) x = _usingCtx.u(f
              ^^^                                    ^^^^^^^^^

 (2:7-10) ng x = fn()             <--  (4:19-20) gCtx.u(fn
              ^^^                                    ^

 (2:7-10) ng x = fn()             <--  (4:20-21) Ctx.u(fn(
              ^^^                                    ^

 (2:7-10) ng x = fn()             <--  (4:21-22) tx.u(fn()
              ^^^                                    ^

(2:10-12) x = fn();               <--  (4:22-24) x.u(fn());
              ^^                                     ^^

(2:12-13) = fn();                 <--  (4:24-25) u(fn());
              ^                                      ^

(2:13-14)  fn();                  <--  (4:25-26) (fn());
              ^                                      ^

(2:14-15) fn();                   <--  (4:26-28) fn());
              ^                                      ^^

 (3:0-15) doSomethingWith(x);     <--   (5:2-17)   doSomethingWith(x);
          ^^^^^^^^^^^^^^^                          ^^^^^^^^^^^^^^^

(3:15-16) With(x);                <--  (5:17-18) With(x);
              ^                                      ^

(3:16-17) ith(x);                 <--  (5:18-19) ith(x);
              ^                                      ^

(3:17-18) th(x);                  <--  (5:19-20) th(x);
              ^                                      ^

(3:18-19) h(x);                   <--  (5:20-21) h(x);
              ^                                      ^

  (4:0-5) after;                  <--    (6:2-7)   after;
          ^^^^^                                    ^^^^^

  (4:5-6) fter;                   <--    (6:7-8) fter;
              ^                                      ^

  (4:6-6) ter;                    <--    (7:0-9) } catch (_) {
             ><                                  ^^^^^^^^^

  (4:6-6) ter;                    <--   (7:9-10) ch (_) {
             ><                                      ^

  (4:6-6) ter;                    <--  (7:10-13) h (_) {
             ><                                      ^^^

  (4:6-6) ter;                    <--   (8:2-11)   _usingCtx.e =
             ><                                    ^^^^^^^^^

  (4:6-6) ter;                    <--  (8:11-12) gCtx.e = 
             ><                                      ^

  (4:6-6) ter;                    <--  (8:12-13) Ctx.e = _
             ><                                      ^

  (4:6-6) ter;                    <--  (8:13-16) tx.e = _;
             ><                                      ^^^

  (4:6-6) ter;                    <--  (8:16-17) e = _;
             ><                                      ^

  (4:6-6) ter;                    <--  (8:17-18)  = _;
             ><                                      ^

  (4:6-6) ter;                    <--   (9:0-11) } finally {
             ><                                  ^^^^^^^^^^^

  (4:6-6) ter;                    <--  (10:2-11)   _usingCtx.d()
             ><                                    ^^^^^^^^^

  (4:6-6) ter;                    <--  (10:11-12) gCtx.d();
             ><                                       ^

  (4:6-6) ter;                    <--  (10:12-13) Ctx.d();
             ><                                       ^

  (4:6-6) ter;                    <--  (10:13-16) tx.d();
             ><                                       ^^^

  (4:6-6) ter;                    <--   (11:0-1) }
             ><                                  ^
