Determine whether the supplied distribution is in the environment.

def dist_is_in_project(self, dist):
        """Determine whether the supplied distribution is in the environment."""
        from .project import _normalized
        prefixes = [
            _normalized(prefix) for prefix in self.base_paths["libdirs"].split(os.pathsep)
            if _normalized(prefix).startswith(_normalized(self.prefix.as_posix()))
        ]
        location = self.locate_dist(dist)
        if not location:
            return False
        location = _normalized(make_posix(location))
        return any(location.startswith(prefix) for prefix in prefixes)