| library /*isNonNullableByDefault*/; | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | static const field core::int annotation = #C1; | 
 | static method f(dynamic x) → dynamic { | 
 |   final dynamic a; | 
 |   { | 
 |     final synthesized dynamic #0#0 = x; | 
 |     if(!(#0#0 is{ForNonNullableByDefault} core::Map<dynamic, dynamic> && #0#0{core::Map<dynamic, dynamic>}.{core::Map::length}{core::int} =={core::num::==}{(core::Object) → core::bool} #C2 && #0#0{core::Map<dynamic, dynamic>}.{core::Map::containsKey}(#C3){(core::Object?) → core::bool} && (let final dynamic #t1 = a = #0#0{core::Map<dynamic, dynamic>}.{core::Map::[]}(#C3){(core::Object?) → dynamic} in true))) | 
 |       throw new core::StateError::•("Pattern matching error"); | 
 |   } | 
 | } | 
 |  | 
 | constants  { | 
 |   #C1 = 0 | 
 |   #C2 = 1 | 
 |   #C3 = "a" | 
 | } |