HARRY
Those names you have – they shouldn’t be a burden. Albus Dumbledore had his trials too you know – and Severus Snape, well, you know all about him—

ALBUS
They were good men.

HARRY
They were great men, with huge flaws, and you know what – those flaws almost made them greater.

Harry Potter and the Cursed Child - Chapter 4 :
See this quote in the Pensive -