ExpansionPanelList constructor

const ExpansionPanelList({Key key, List<ExpansionPanel> children: const [], ExpansionPanelCallback expansionCallback, Duration animationDuration: kThemeAnimationDuration })

Creates an expansion panel list widget. The expansionCallback is triggered when an expansion panel expand/collapse button is pushed.

The children and animationDuration arguments must not be null.

Implementation 

const ExpansionPanelList({
  Key key,
  this.children = const <ExpansionPanel>[],
  this.expansionCallback,
  this.animationDuration = kThemeAnimationDuration,
}) : assert(children != null),
     assert(animationDuration != null),
     _allowOnlyOnePanelOpen = false,
     initialOpenPanelValue = null,
     super(key: key);