// Find the provider node ...
MutableCachedNode providerNode = system.mutable(providerKey);
// And remove the index defn from the provider ...
final NodeKey key = nodeKey(providerNode.getKey(), indexDefn);
providerNode.removeChild(system, key);
system.destroy(key);
// If there are no more children under the provider, remove it, too...
if (providerNode.getChildReferences(system).isEmpty()) {
indexes.removeChild(system, providerKey);