You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: objdiff.rb
    path of file: ./repos/grinder/node/lib/metasm/misc
    
    the code of the file until where you have to start completion: #    This file is part of Metasm, the Ruby assembly manipulation suite
#    Copyright (C) 2006-2009 Yoann GUILL
    
def Object.diff(o1, o2)
	if o1.class == o2.class
		h = {}
		case o1
		when Array, Hash
			if o1.kind_of? Array
				keys = (0...[o1.length, o2.length].max).to_a
			else
				keys = o1.keys | o2.keys
			end