code: private Set<String> getDependenciesForClass(String clsName) {
          Set<String> dependencies = dependencyGraph.get(clsName);
          if (dependencies == null) {
              dependencies = new HashSet<>();
              dependencyGraph.put(clsName, dependencies);
          }
  
          return dependencies;
      }
docs: returns a set of dependent class names for a class, and if it doesn't exist create the set install it, and then return;
  
  @param clsName
  the class for which you are trying to get dependencies
  @return the active set of classes that are dependent on the specified class