convertMaskConfig = (maskConfig) => {
    let bandIds = [];
    if (maskConfig != null && Array.isArray(maskConfig['bandId'])) {
      bandIds = maskConfig['bandId'].map((bandId) => bandId || '');
    }
    // TODO(user): Tileset ID is always set to the default of the empty
    // string, if we decide to set the tilesetId on the OnePlatform tileset
    // we need to change this.
    return new ee.api.TilesetMaskBand({tilesetId: tileset['id'] || '', bandIds});
  }
Return a TilesetMaskBand  for a given maskConfig.  If the maskConfig
 is null the default is to return a TilesetMaskBand for all bands
 (No bandIds set).

 @param {?Object} maskConfig the old-manifest maskConfig.
 @return {!ee.api.TilesetMaskBand}