// must not try send a patch to the server!

    // just deletes the statements; watchers are unaffected.

    this.cachedFloatValues = new Map(); // s + '|' + p -> number

    this.cachedUriValues = new Map(); // s + '|' + p -> Uri

    this._applyPatch(patchToDeleteEntireGraph(this.graph));

    // if we had a Store already, this lets N3.Store free all its indices/etc

    this.graph = new N3.Store();

    this.rebuildPrefixFuncs(this.prefixes);

  }

  _clearGraphOnNewConnection() {

    // must not try send a patch to the server

    log("clearGraphOnNewConnection");

    this.clearGraph();

    log("clearGraphOnNewConnection done");

    if (this.clearCb != null) {

      return this.clearCb();

    }

  }

  private rebuildPrefixFuncs(prefixes: Map<string, string>) {

    const p = Object.create(null);

    prefixes.forEach((v: string, k: string) => (p[k] = v));

    this.prefixFuncs = N3.Util.prefixes(p);

    return this.prefixFuncs;

  }

  U() {

    // just a shorthand

    return this.Uri.bind(this);

  }

  Uri(curie: string) {

    if (curie == null) {

      throw new Error("no uri");

    }

    if (curie.match(/^http/)) {

      return N3.DataFactory.namedNode(curie);

    }

    const part = curie.split(":");

    return this.prefixFuncs(part[0])(part[1]);

  }

  // Uri(shorten(u)).value==u

  shorten(uri: N3.NamedNode): string {

    }

    return uri.value;

  }

  Literal(jsValue: string | number) {

    return N3.DataFactory.literal(jsValue);

  }

  LiteralRoundedFloat(f: number) {

    return N3.DataFactory.literal(f.toPrecision(3), this.Uri("http://www.w3.org/2001/XMLSchema#double"));

  }

  Quad(s: any, p: any, o: any, g: any) {

    return N3.DataFactory.quad(s, p, o, g);

  }

  toJs(literal: { value: any }) {

    // incomplete

    return parseFloat(literal.value);

  }

  loadTrig(trig: any, cb: () => any) {

    // for debugging

    const adds: Quad[] = [];

    const parser = new N3.Parser();

    parser.parse(trig, (error: any, quad: any, prefixes: any) => {

      if (error) {

        throw new Error(error);

      }

      if (quad) {

        adds.push(quad);

      } else {

        this._applyPatch(new Patch([], adds));

        // todo: here, add those prefixes to our known set

        if (cb) {

          cb();

        }

      }

    });

  }

  quads(): any {

    // for debugging

    return Array.from(this.graph.getQuads(null, null, null, null)).map((q: Quad) => [q.subject, q.predicate, q.object, q.graph]);

  }

  applyAndSendPatch(patch: Patch) {

    console.time("applyAndSendPatch");