code: private Map<Long, FeatureShape> getFeatureIds(Map<String, Map<Long, FeatureShape>> tables, String table) {
  
          Map<Long, FeatureShape> featureIds = tables.get(table);
          if (featureIds == null) {
              featureIds = new HashMap<>();
              tables.put(table, featureIds);
          }
          return featureIds;
      }
docs: Get the feature ids and map shapes for the tables and table
  
  @param tables tables
  @param table  table name
  @return feature ids to map shapes mapping