Step constructor

const Step({@required Widget title, Widget subtitle, @required Widget content, StepState state: StepState.indexed, bool isActive: false })

Creates a step for a Stepper.

The title, content, and state arguments must not be null.

Implementation 

const Step({
  @required this.title,
  this.subtitle,
  @required this.content,
  this.state = StepState.indexed,
  this.isActive = false,
}) : assert(title != null),
     assert(content != null),
     assert(state != null);