Although the [Tutorial - User Guide](../tutorial/index.md){.internal-link target=_blank} and this **Advanced User Guide** are written as a guided tutorial (like a book) and should be enough for you to **learn FastAPI**, you might want to complement it with additional courses.

Or it might be the case that you just prefer to take other courses because they adapt better to your learning style.

@GwtIncompatible // TreeRangeSet
public abstract class AbstractRangeSetTest extends TestCase {
  public static void testInvariants(RangeSet<?> rangeSet) {
    testInvariantsInternal(rangeSet);
    testInvariantsInternal(rangeSet.complement());
  }

  private static <C extends Comparable<?>> void testInvariantsInternal(RangeSet<C> rangeSet) {
    assertEquals(rangeSet.asRanges().isEmpty(), rangeSet.isEmpty());

//
// If operating in binary mode, this assumes strict GNU binary mode; which means
// that the first byte can only be either 0x80 or 0xff. Thus, the first byte is
// equivalent to the sign bit in two's complement form.
func fitsInBase256(n int, x int64) bool {
	binBits := uint(n-1) * 8
	return n >= 9 || (x >= -1<<binBits && x < 1<<binBits)
}

// parseNumeric parses the input as being encoded in either base-256 or octal.