constructor(tileStates) {
    const tileGrid = new TileGrid({
      resolutions: [360 / 256, 180 / 256, 90 / 256, 45 / 256],
      origin: [-180, -180],
      tileSize: 256,
    });

    super({
      projection: getProjection('EPSG:4326'),
      tileGrid: tileGrid,
    });

    this.tileStates = tileStates;
  }
Tile source for tests that uses a EPSG:4326 based grid with 4 resolutions and
256x256 tiles.

@param {Object<string, import('../../../../../src/ol/TileState.js').default>} tileStates Lookup of tile key to
    tile state.