src/vs/workbench/api/common/extHostExtensionService.ts/AbstractExtHostExtensionService/getExtensionPathIndex
class AbstractExtHostExtensionService:	public async getExtensionPathIndex(): Promise<TernarySearchTree<URI, IExtensionDescription>> {
		if (!this._extensionPathIndex) {
			this._extensionPathIndex = (async () => {
				const tst = TernarySearchTree.forUris<IExtensionDescription>(key => {
					// using the default/biased extUri-util because the IExtHostFileSystemInfo-service
					// isn't ready to be used yet, e.g the knowledge about `file` protocol and others
					// comes in while this code runs
					return extUriBiasedIgnorePathCase.ignorePathCasing(key);
				});
				// const tst = TernarySearchTree.forUris<IExtensionDescription>(key => true);
				for (const ext of this._registry.getAllExtensionDescriptions()) {
					if (this._getEntryPoint(ext)) {
						const uri = await this._realPathExtensionUri(ext.extensionLocation);
						tst.set(uri, ext);
					}
				}
				return tst;
			})();
		}
		return this._extensionPathIndex;
	}