code: public Map<String, Variable> getReferencedClassVariables() {
          if (referencedClassVariables == Collections.EMPTY_MAP) {
              return referencedClassVariables;
          } else {
              return Collections.unmodifiableMap(referencedClassVariables);
          }
      }
docs: Gets a map containing the class variables referenced
  by this scope. This not can not be modified.
  @return a map containing the class variable references