Breakpoints are flags telling the debugger you want to step through certain lines of code
'b' will list all open breakpoints
'b <line number>' will set a breakpoint on that line of the current file
'del <breakpoint number>' will delete a breakpoint
(rdb:1) b 19
Set breakpoint 1 at test-rdb:19
(rdb:1) b
Breakpoints:
1 test-rdb:19
(rdb:1) del 1
(rdb:1) b 19
Set breakpoint 2 at test-rdb:19
(rdb:1) b
Breakpoints:
2 test-rdb:19