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: expression.rb
    path of file: ./repos/grinder/node/lib/metasm/tests
    
    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 GUILLOT
#
#    Licence is LGPL, see LICENCE in the top-level directory


requi
    
	def test_pattern
		pat = E[:a, :+, [:b, :&, 0xffff]].match(E['a', :|, 'b'], 'a', 'b')
		assert_equal(false, pat)

		pat = E[:a, :+, [:b, :&, 0xffff]].match(E['a', :+, 'b'], 'a', 'b')
		assert_equal(:a, pat['a'])
		p2 = pat['b'].match(E[:a, :b, :c], :a, :b, :c)
		assert_equal(0xffff, p2[:c])
		assert_equal(:&, p2[:b])
	end