private inline fun <T> assertOnFileDescriptor(
    content: String? = null,
    fn: (FileDescriptor) -> T,
  ): T {
    return assertOnPath(content) {
      FileInputStream(filePath.toFile()).use { fis ->
        fn(fis.fd)
      }
    }
  }

  private inline fun <T> assertOnPath(
    content: String? = null,
    fn: (okio.Path) -> T,
  ): T {
    FileSystem.SYSTEM.write(filePath) {