tdcommon/src/main/java/thredds/server/catalog/ConfigCatalog.java
public CatalogBuilder makeCatalogBuilder() {
    CatalogBuilder builder = new CatalogBuilder(this);
    for (Dataset ds : getDatasetsLocal()) {
      builder.addDataset(makeDatasetBuilder(null, ds));
    }
    return builder;
  }
public CatalogBuilder makeCatalogBuilder() {
    CatalogBuilder builder = new CatalogBuilder(this);
    for (Dataset ds : getDatasetsLocal()) {
      builder.addDataset(makeDatasetBuilder(null, ds));
    }
    return builder;
  }
turn ConfigCatalog into a mutable CatalogBuilder so we can mutate