# Introduction In this lab, we have a code snippet that includes a function called `conditional_function()`, but it will only be compiled and executed if a custom conditional called `some_condition` is passed to `rustc` using the `--cfg` flag. > **Note:** If the lab does not specify a file name, you can use any file name you want. For example, you can use `main.rs`, compile and run it with `rustc main.rs && ./main`.
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