The grid component supports optionally showing nested row base on a predicate, at the first-level depth.
This means that conditionally always-shown rows (ie rows that return true
from the showRowWhenCollapsed
predicate) will be shown even if the parent is not expanded.
Although, if the parent is in turn a child of a collapsed parent, they will not be shown.
showRowWhenCollapsed
is null
by default, so all rows will be hidden when the parent row is collapsed.