prepareRename method
Checks whether the symbol at position can be renamed, returning its range
and current text, or null if it cannot (no identifier under the cursor).
Implementation
Future<PrepareRenameResult?> prepareRename(
String uri,
Position position,
) async {
final r = await _positional('textDocument/prepareRename', uri, position);
return r is Map
? PrepareRenameResult.fromJson(r.cast<String, Object?>())
: null;
}