java.lang.StackOverflowError. Why am I getting a Stackoverflow exception here

I have a list of items that are parents and children, displayed in a hierarchy. I want to toggle their `expanded` property. so if a parent is clicked and the parent's children are showing then all of the parents children will be collapsed and vice versa Stackoverflow trace points to this line ``` if (childItem.getItemId() == item.getItemId()) { hideItemAndDescendants(childItem); //causing stack overflow } ``` I under stand that a stackoverflow occurs when a method keeps calling it self infinitely .but in this case i have a For loop that only loops over the `items` list and the list size is only around 10. ``` public boolean toggleNodeCollapseState(long itemId) { boolean changed = false; // a flag to determine if anything collapsed or expanded for (int i = 0; i < items.size(); i++) { Item childItem = items.get(i); if (childItem.getParentItemId() == itemId) { changed = true; childItem.setCollapsed(!childItem.isCollapsed()); if (childItem.isCollapsed()) { hideItemAndDescendants(childItem); } else { showDescendants(childItem); } } } return changed; } public void hideItemAndDescendants(Item item) { item.hide(); for (int i = 0; i < items.size(); i++) { Item childItem = items.get(i); if (childItem.getItemId() == item.getItemId()) { hideItemAndDescendants(childItem); } } } public void showDescendants(Item item) { item.hide(); for (int i = 0; i < items.size(); i++) { Item childItem = items.get(i); if (childItem.getItemId() == item.getItemId()) { childItem.show(); if (!childItem.isCollapsed()) { showDescendants(childItem); } } } } ```