code: public static <T extends Throwable> Either<T, Unit> trying(CheckedRunnable<T> runnable) {
          return trying(runnable, id());
      }
docs: Attempt to execute the {@link CheckedRunnable}, returning {@link Unit} in a right value. If the runnable throws
  exception, wrap it in a left value and return it.
  
  @param runnable the runnable
  @param <T>      the left parameter type (the most contravariant exception that runnable might throw)
  @return {@link Unit} as a right value, or a left value of the thrown exception