//
	// From high to low bit position, wall encodes a 1-bit flag (hasMonotonic),
	// a 33-bit seconds field, and a 30-bit wall time nanoseconds field.
	// The nanoseconds field is in the range [0, 999999999].
	// If the hasMonotonic bit is 0, then the 33-bit field must be zero
	// and the full signed 64-bit wall seconds since Jan 1 year 1 is stored in ext.
	// If the hasMonotonic bit is 1, then the 33-bit field holds a 33-bit

	if (std >> stdSeparatorShift) == 0 {
		return '.'
	}
	return ','
}

// appendNano appends a fractional second, as nanoseconds, to b
// and returns the result. The nanosec must be within [0, 999999999].
func appendNano(b []byte, nanosec int, std int) []byte {
	trim := std&stdMask == stdFracSecond9
	n := digitsLen(std)
	if trim && (n == 0 || nanosec == 0) {
		return b
	}
	dot := separator(std)

		}
	}
}

func TestAddToExactSecond(t *testing.T) {
	// Add an amount to the current time to round it up to the next exact second.
	// This test checks that the nsec field still lies within the range [0, 999999999].
	t1 := Now()
	t2 := t1.Add(Second - Duration(t1.Nanosecond()))
	sec := (t1.Second() + 1) % 60
	if t2.Second() != sec || t2.Nanosecond() != 0 {