Question about memory_leak_analysis

[xluffy]

In section 3, https://koute.github.io/bytehound/memory_leak_analysis.html, I try to follow your script

let remaining = allocations().only_not_matching_backtraces(groups);

Throw ERROR: Variable not found: groups (line 1, position 60) error

So I try to filter out all of allocations previous section. But I'm not sure what is all of allocation? I have 2 options

let groups = allocations()
    .only_leaked();
let remaining = allocations().only_not_matching_backtraces(groups);

or

let groups = allocations()
let remaining = allocations().only_not_matching_backtraces(groups);

But I don't know which one is correct.