The ExpansionPanel enables you to set its initial expanded state and change it on demand by using the available API options.
By default, the ExpansionPanel is collapsed. To expand it, set the expanded property to
true. The property supports two-way binding and can be programmatically updated to immediately expand or collapse the ExpansionPanel.
You can switch between the expanded and collapsed states of the ExpansionPanel by making use of is toggle method. The difference between this approach and the one where the expanded state is set initially is that the toggle method will trigger the animation, which is specified in the configuration options of the ExpansionPanel.