private static Map<String, String> getCatalogProperties(
      Configuration conf, String catalogName, String catalogType) {
    Map<String, String> catalogProperties = Maps.newHashMap();
    String keyPrefix = InputFormatConfig.CATALOG_CONFIG_PREFIX + catalogName;
    conf.forEach(config -> {
      if (config.getKey().startsWith(InputFormatConfig.CATALOG_DEFAULT_CONFIG_PREFIX)) {
        catalogProperties.putIfAbsent(
                config.getKey().substring(InputFormatConfig.CATALOG_DEFAULT_CONFIG_PREFIX.length()),
                config.getValue());
      } else if (config.getKey().startsWith(keyPrefix)) {
        catalogProperties.put(
                config.getKey().substring(keyPrefix.length() + 1),
                config.getValue());
      }
    });

    return catalogProperties;
  }
Collect all the catalog specific configuration from the global hive configuration.
@param conf a Hadoop configuration
@param catalogName name of the catalog
@param catalogType type of the catalog
@return complete map of catalog properties
iceberg/iceberg-handler/src/main/java/org/apache/iceberg/mr/Catalogs.java