Go playground: https://go.dev/play/p/9HKvgvSWqH3
start=0xc000100000 len=65536 cap=65536 end=0xc000110000 (start == nil) is false, (end == nil) is false, (buf == nil) is false
start=0xc000108000 len= 32 cap=32768 end=0xc000110000 (start == nil) is false, (end == nil) is false, (buf == nil) is false
start=0xc00010fff0 len= 16 cap= 16 end=0xc000110000 (start == nil) is false, (end == nil) is false, (buf == nil) is false
start=0xc00010ffff len= 1 cap= 1 end=0xc000110000 (start == nil) is false, (end == nil) is false, (buf == nil) is false
start=0xc000100000 len= 0 cap= 0 end=0xc000100000 (start == nil) is false, (end == nil) is false, (buf == nil) is false
start= len= 0 cap= 0 end= (start == nil) is false, (end == nil) is false, (buf == nil) is true