function computeChildMask(quadKey, info, metadata) {
  let childMask = info.getChildBitmask();
  if (info.terrainState === TerrainState.PARENT) {
    childMask = 0;
    for (let i = 0; i < 4; ++i) {
      const child = metadata.getTileInformationFromQuadKey(
        quadKey + i.toString(),
      );
      if (defined(child) && child.hasTerrain()) {
        childMask |= 1 << i;
      }
    }
  }

  return childMask;
}
Creates a GoogleEarthTerrainProvider from GoogleEarthEnterpriseMetadata

@param {GoogleEarthEnterpriseMetadata} metadata A metadata object that can be used to share metadata requests with a GoogleEarthEnterpriseImageryProvider.
@param {GoogleEarthEnterpriseTerrainProvider.ConstructorOptions} options An object describing initialization options
@returns {GoogleEarthEnterpriseTerrainProvider}

@see GoogleEarthEnterpriseMetadata.fromUrl

@exception {RuntimeError} metadata does not specify terrain

@example
const geeMetadata = await GoogleEarthEnterpriseMetadata.fromUrl("http://www.example.com");
const gee = Cesium.GoogleEarthEnterpriseTerrainProvider.fromMetadata(geeMetadata);