|  | beginCompilationUnit(f) | 
|  | beginMetadataStar(f) | 
|  | endMetadataStar(0) | 
|  | beginTopLevelMember(f) | 
|  | beginTopLevelMethod(, null) | 
|  | handleNoType() | 
|  | handleIdentifier(f, topLevelFunctionDeclaration) | 
|  | handleNoTypeVariables(() | 
|  | beginFormalParameters((, MemberKind.TopLevelMethod) | 
|  | endFormalParameters(0, (, ), MemberKind.TopLevelMethod) | 
|  | handleAsyncModifier(null, null) | 
|  | beginBlockFunctionBody({) | 
|  | beginMetadataStar(var) | 
|  | endMetadataStar(0) | 
|  | handleNoType(var) | 
|  | beginVariablesDeclaration(a, null, var) | 
|  | handleIdentifier(a, localVariableDeclaration) | 
|  | beginInitializedIdentifier(a) | 
|  | handleNoVariableInitializer(a) | 
|  | endInitializedIdentifier(a) | 
|  | endVariablesDeclaration(1, ;) | 
|  | beginReturnStatement(return) | 
|  | handleIdentifier(a, expression) | 
|  | handleNoTypeArguments(!=) | 
|  | handleNoArguments(!=) | 
|  | handleSend(a, !=) | 
|  | beginBinaryExpression(!=) | 
|  | handleLiteralNull(null) | 
|  | endBinaryExpression(!=) | 
|  | beginConditionalExpression(?) | 
|  | handleNoTypeArguments([) | 
|  | handleIdentifier(a, expression) | 
|  | handleNoTypeArguments(]) | 
|  | handleNoArguments(]) | 
|  | handleSend(a, ]) | 
|  | handleLiteralList(1, [, null, ]) | 
|  | handleConditionalExpressionColon() | 
|  | beginConstLiteral([]) | 
|  | handleNoTypeArguments([]) | 
|  | handleLiteralList(0, [, const, ]) | 
|  | endConstLiteral(;) | 
|  | endConditionalExpression(?, :) | 
|  | endReturnStatement(true, return, ;) | 
|  | endBlockFunctionBody(2, {, }) | 
|  | endTopLevelMethod(f, null, }) | 
|  | endTopLevelDeclaration() | 
|  | endCompilationUnit(1, ) |