How to use the @bentley/bentleyjs-core.Id64.getUpperUint32 function in @bentley/bentleyjs-core

public overrideSubCategory(id: Id64String, app: Appearance, replaceExisting: boolean = true): void {
      // NB: We used to do nothing if this.isSubCategoryVisible() => false but now models can turn invisible subcategories visible in their own context.
      const idLo = Id64.getLowerUint32(id);
      const idHi = Id64.getUpperUint32(id);

      // NB: Appearance may specify no overridden symbology - this means "don't apply the default overrides to this subcategory"
      if (replaceExisting || undefined === this.getSubCategoryOverrides(idLo, idHi))
        this._subCategoryOverrides.set(idLo, idHi, app);
    }

public async saveThumbnail(viewId: Id64String, thumbnail: ThumbnailProps): Promise {
      const val = new Uint8Array(thumbnail.image.length + 24);  // include the viewId and metadata in the binary transfer by allocating a new buffer 24 bytes larger than the image size
      new Uint32Array(val.buffer, 0, 4).set([thumbnail.image.length, thumbnail.format === "jpeg" ? ImageSourceFormat.Jpeg : ImageSourceFormat.Png, thumbnail.width, thumbnail.height]); // metadata at offset 0
      const low32 = Id64.getLowerUint32(viewId);
      const high32 = Id64.getUpperUint32(viewId);
      new Uint32Array(val.buffer, 16, 2).set([low32, high32]); // viewId is 8 bytes starting at offset 16
      val.set(thumbnail.image, 24); // image data at offset 24
      return IModelWriteRpcInterface.getClient().saveThumbnail(this._iModel.iModelToken.toJSON(), val);
    }
  }

          case VariableValueTypes.Id64Array: return (actualValue as string[]).map((id) => Id64.getUpperUint32(id));
          default: return undefined;

private changeValueType(actualValue: VariableValue, fromType: VariableValueTypes, toType: VariableValueTypes): VariableValue | undefined {
    switch (toType) {
      case VariableValueTypes.Bool:
        switch (fromType) {
          case VariableValueTypes.Int: return (0 !== actualValue);
          case VariableValueTypes.Id64: return Id64.isValidId64(actualValue as string);
          default: return undefined;
        }
      case VariableValueTypes.Int:
        switch (fromType) {
          case VariableValueTypes.Bool: return actualValue ? 1 : 0;
          case VariableValueTypes.Id64: return Id64.getUpperUint32(actualValue as string);
          default: return undefined;
        }
      case VariableValueTypes.IntArray:
        switch (fromType) {
          case VariableValueTypes.Id64Array: return (actualValue as string[]).map((id) => Id64.getUpperUint32(id));
          default: return undefined;
        }
      case VariableValueTypes.Id64:
        switch (fromType) {
          case VariableValueTypes.Bool: return Id64.fromLocalAndBriefcaseIds(actualValue ? 1 : 0, 0);
          case VariableValueTypes.Int: return Id64.fromLocalAndBriefcaseIds(actualValue as number, 0);
          default: return undefined;
        }
      case VariableValueTypes.Id64Array:
        switch (fromType) {
          case VariableValueTypes.IntArray: return (actualValue as number[]).map((int) => Id64.fromLocalAndBriefcaseIds(int, 0));

});

      this._constructions = constructions;
      this._dimensions = dimensions;
      this._patterns = patterns;
      this._lineWeights = viewFlags.weights;

      for (const categoryId of view.categorySelector.categories) {
        const subCategoryIds = view.iModel.subcategories.getSubCategories(categoryId);
        if (undefined === subCategoryIds)
          continue;

        for (const subCategoryId of subCategoryIds) {
          if (view.isSubCategoryVisible(subCategoryId)) {
            const idLo = Id64.getLowerUint32(subCategoryId);
            const idHi = Id64.getUpperUint32(subCategoryId);
            this._visibleSubCategories.add(idLo, idHi);
          }
        }
      }
    }

    public getElementOverridesById(id: Id64String): Appearance | undefined { return this.getElementOverrides(Id64.getLowerUint32(id), Id64.getUpperUint32(id), 0); }
    /** Returns the overrides applied to geometry belonging to the specified subcategory, if any such are defined. */