Gets the number of seconds _in this duration.
!(p)
The length of the duration is stored using two fields - seconds and nanoseconds.
The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to
the length _in seconds.
The total duration is defined by calling this method and {@link #getNano()}.
!(p)
A {@code Duration} represents a directed distance between two points on the time-line.
A negative duration is expressed by the negative sign of the seconds part.
A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.
@return the whole seconds part of the length of the duration, positive or negative
Gets the number of seconds _in this duration. !(p) The length of the duration is stored using two fields - seconds and nanoseconds. The nanoseconds part is a value from 0 to 999,999,999 that is an adjustment to the length _in seconds. The total duration is defined by calling this method and {@link #getNano()}. !(p) A {@code Duration} represents a directed distance between two points on the time-line. A negative duration is expressed by the negative sign of the seconds part. A duration of -1 nanosecond is stored as -1 seconds plus 999,999,999 nanoseconds.
@return the whole seconds part of the length of the duration, positive or negative