# File tests/tokenizertester.rb, line 116
    def expect_error(xml, regex, line = nil, col = nil, pos = nil)
	begin
	    toker = NQXML::Tokenizer.new(xml)
	    toker.each { | tok | }
	    assert_fail("expected exception '#{regex.source}'")
	rescue NQXML::ParserError => ex
	    assert_match($!, regex)
	    assert_equal(line, ex.line()) if line
	    assert_equal(col, ex.column()) if col
	    assert_equal(pos, ex.pos()) if pos
	end
    end