code: public static boolean isAbstractClass (@Nullable final Class <?> aClass)
    {
      // Special case for arrays (see documentation of Class.getModifiers: only
      // final and interface are set, the rest is indeterministic)
      return aClass != null && !aClass.isArray () && Modifier.isAbstract (aClass.getModifiers ());
    }
docs: Check if the passed class is abstract or not. Note: interfaces and
  annotations are also considered as abstract whereas arrays are never
  abstract.
  
  @param aClass
  The class to check.
  @return <code>true</code> if the passed class is abstract