message: Avoid declaring same type twice in test/typescript.ts.
diff: @@ -42,7 +42,7 @@ var nodeMajorVersion = parseInt(process.versions.node, 10);
  'type G = undefined;',
  'type H = bigint;',
  '',
  - 'type C = {',
  + 'type I = {',
  ' a: string,',
  ' b?: number',
  '};'
  