code: @Nullable
    public static String getClassPackageName (@Nullable final Class <?> aClass)
    {
      return aClass == null ? null : getClassPackageName (aClass.getName ());
    }
docs: Get the name of the package the passed class resides in.
  
  @param aClass
  The class to get the information from. May not be <code>null</code>.
  @return The package name of the passed class.