addClassesToNamespace(i, a) {
    if (this.namespaces.has(i))
      for (const u of a) {
        const { className: l } = this.splitClassNameAndType(u);
        this.classes.get(l).parent = i, this.namespaces.get(i).classes.set(l, this.classes.get(l));
      }
  }
Function called by parser when a namespace definition has been found.

@param id - Id of the namespace to add
@param classNames - Ids of the class to add
@public