Heidi is preparing her tax return for the year and is looking at ways to save on her tax bill. Heidi worked full time in the day and tended bar at night. Her daytime employer reported her income for her job, but her tips from tending bar at night were not reported to the IRS. Heidi is thinking about leaving the tip earnings out of her income on her tax return. Is this tax evasion or tax avoidance? Discuss in details.