1.67.1 Duration class: instance creation
- days: d
- Answer a duration of `d' days
- days: d hours: h minutes: m seconds: s
- Answer a duration of `d' days and the given number of hours,
minutes, and seconds.
- Initialize the receiver's instance variables
- readFrom: aStream
- Parse an instance of the receiver (hours/minutes/seconds) from
- Answer a duration of zero seconds.