collapsed property
This field is true if this group is collapsed.
A collapsed group remains collapsed if an overlapping group at a shallower depth is expanded. A true value does not imply that all dimensions within the group are hidden, since a dimension's visibility can change independently from this group property. However, when this property is updated, all dimensions within it are set to hidden if this field is true, or set to visible if this field is false.
Implementation
core.bool? collapsed;