Minimal example for profiling neovim

Hi! Do you have a minimal example for how to use this to profile something in neovim? I tried for example ```lua local func = function() print("sleeping") vim.system({"sleep", "2"}):wait() print("done") end vim.cmd.PerfLuaProfileStart() func() P(vim.diagnostic.get(0, {})) vim.cmd.PerfLuaProfileStop() ``` but it didn't show anything (other than the message that "Callgraph has been loaded")