When racket/unit is used as a language name with #lang, the module body is treated as a unit body. The body must match the following module-body grammar:
|require-decl||=||(require require-spec ...)|
||||(begin require-decl ...)|
After any number of require-decls, the content of the module is the same as a unit body.
The resulting unit is exported as base@, where base is derived from the enclosing module’s name (i.e., its symbolic name, or its path without the directory and file suffix). If the module name ends in -unit, then base corresponds to the module name before -unit. Otherwise, the module name serves as base.