MICROSECONDS_PER_SECOND constant
int MICROSECONDS_PER_SECOND = MICROSECONDS_PER_MILLISECOND * MILLISECONDS_PER_SECOND© 2012 the Dart project authors
Licensed under the Creative Commons Attribution-ShareAlike License v4.0.
https://api.dartlang.org/stable/1.24.3/dart-core/Duration/MICROSECONDS_PER_SECOND-constant.html