"version" of the tree's state. Will be incremented on any removal/adding
the element. On the iteration's start, range will record the current
"version" of the tree, and, and before proceeding with the iteration,
it will check if any changes were performed on the tree, to prevent
iteration over an undefined region.
structBTreeMapImplementation(KeyType, ValueType, int tree_degree)
"version" of the tree's state. Will be incremented on any removal/adding the element. On the iteration's start, range will record the current "version" of the tree, and, and before proceeding with the iteration, it will check if any changes were performed on the tree, to prevent iteration over an undefined region.