Filter negation

[fukawi2]

Apologies if this is in the docs, but I couldn't find it.

Is it possible to negate filters? For example, one of my filters I want to ignore GitHub issues with a certain prefix in the title. I'm aware of ne to negate a whole string, but I want to negate a prefix filter in this instance:

"Filters": [
    "{{test not HasPrefix .title \"IDontCare:\"}}",
    "{{test ne .username \"fukawi2\"}}"
]

Beehive hasn't complained about the above syntax, but I'm not sure if it will actually work or not?