build/lib/tsb/builder.ts/LanguageServiceHost/constructor
class LanguageServiceHost:	constructor(
		private readonly _cmdLine: ts.ParsedCommandLine,
		private readonly _projectPath: string,
		private readonly _log: (topic: string, message: string) => void
	) {
		this._snapshots = Object.create(null);
		this._filesInProject = new Set(_cmdLine.fileNames);
		this._filesAdded = new Set();
		this._dependencies = new utils.graph.Graph<string>(s => s);
		this._dependenciesRecomputeList = [];
		this._fileNameToDeclaredModule = Object.create(null);

		this._projectVersion = 1;
	}