public void cannot_parse_invalid_input(string input, int level)
{
var result = HeadingParser.GetParser(level)(new Input(input));
Assert.False(result.WasSuccessful && result.Remainder.AtEnd);
}
public void can_parse_valid_input(string input, int level, string expected)
{
var result = HeadingParser.GetParser(level).Parse(input);
Assert.Equal(expected, result);
}