Checker Error Reporting

The checker uses the local error function to report errors. Here is the function:

function error(location: Node, message: DiagnosticMessage, arg0?: any, arg1?: any, arg2?: any): void {
let diagnostic = location
? createDiagnosticForNode(location, message, arg0, arg1, arg2)
: createCompilerDiagnostic(message, arg0, arg1, arg2);
diagnostics.add(diagnostic);
}