code: public List<Class<?>> getSiblingClasses(final Class<?> clazz, boolean recursive, final Predicate<Class<?>> predicate)
  	{
  		return getClasses(getPackages(clazz)[0], recursive, predicate);
  	}
docs: Find all the classes that are siblings of the provided class
  
  @param clazz
  the class in whose package to search
  @param recursive
  if true, search all the child packages of the package containing the class
  @param predicate
  an optional additional predicate to filter the list against
  
  @return