} else if offsetEnd < 0 {
			return nil, fmt.Errorf("Last byte position is negative ('%d')", offsetEnd)
		}
	}

	switch {
	case offsetBegin > -1 && offsetEnd > -1:
		if offsetBegin > offsetEnd {
			return nil, errInvalidRange
		}
		return &HTTPRangeSpec{false, offsetBegin, offsetEnd}, nil
	case offsetBegin > -1:
		return &HTTPRangeSpec{false, offsetBegin, -1}, nil

		}

		if start != successCase.offsetBegin {
			t.Fatalf("expected: %d, got: %d", successCase.offsetBegin, start)
		}

		if start+length-1 != successCase.offsetEnd {
			t.Fatalf("expected: %d, got: %d", successCase.offsetEnd, start+length-1)
		}
	}

	// Test invalid range strings.
	invalidRangeStrings := []string{
		"bytes=8",
		"bytes=5-2",
		"bytes=+2-5",
		"bytes=2-+5",
		"bytes=2--5",