Checks if this duration is negative, excluding zero.
!(p)
A {@code Duration} represents a directed distance between two points on
the time-line and can therefore be positive, zero or negative.
This method checks whether the length is less than zero.
@return true if this duration has a total length less than zero
Checks if this duration is negative, excluding zero. !(p) A {@code Duration} represents a directed distance between two points on the time-line and can therefore be positive, zero or negative. This method checks whether the length is less than zero.
@return true if this duration has a total length less than zero