getNameOrDottedNameSpan(fileName, startPos, endPos) {
          return this.forwardJSONCall(
            `getNameOrDottedNameSpan('${fileName}', ${startPos}, ${endPos})`,
            () => this.languageService.getNameOrDottedNameSpan(fileName, startPos, endPos)
          );
        }
Computes span information of the name or dotted name at the requested position
in the active file.