code: public Map<String, Edge> getEdgeCache(boolean includeUserDefined, boolean includeAutoGenerated) {
      return loader.getEdgeCache(includeUserDefined, includeAutoGenerated);
    }
docs: Returns a cache that contains a mapping from variables to edge instances.
  
  @param includeUserDefined true, iff user-defined variables shall be included in the cache
  @param includeAutoGenerated true, iff auto-generated variables shall be included in the cache
  
  @return immutable edge cache