# File tests/treeparsertester.rb, line 90
    def expect_error(xml, regex, line = nil, col = nil, pos = nil)
	parser = nil
	begin
	    parser = NQXML::TreeParser.new(xml)
	    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