Why doesn't `ts-morph` have a `isSourceFileDefaultLibrary` function like `typescript`?

[`microsoft/TypeScript/src/compiler/program.ts`](https://github.com/microsoft/TypeScript/blob/5aa0053c74f0c67b2cbedf9cee6607ead3b9dc45/src/compiler/program.ts#L2006-L2028) has a `isSourceFileDefaultLibrary` `function`.

```ts
function isSourceFileDefaultLibrary(file: SourceFile): boolean {
if (!file.isDeclarationFile) {
return false;
}

if (file.hasNoDefaultLib) {
return true;
}

if (!options.noLib) {
return false;
}

// If '--lib' is not specified, include default library file according to '--target'
// otherwise, using options specified in '--lib' instead of '--target' default library file
const equalityComparer = host.useCaseSensitiveFileNames() ? equateStringsCaseSensitive : equateStringsCaseInsensitive;
if (!options.lib) {
return equalityComparer(file.fileName, getDefaultLibraryFileName());
}
else {
return some(options.lib, libFileName => equalityComparer(file.fileName, pathForLibFile(libFileName)));
}
}
```

I was just curious: why does this repository [have `isSourceFileFromExternalLibrary`](https://github.com/dsherret/ts-morph/search?q=isSourceFileFromExternalLibrary), but not [`isSourceFileDefaultLibrary`](https://github.com/dsherret/ts-morph/search?q=isSourceFileDefaultLibrary)?

On a sidenote, how do you feel about creating a Discussions section for more discussion-based questions like this one?