Implement the following function as a new function for the linked list toolkit. Do not call any of the other toolkit functions from within your implementation. (Use the usual node definition with member variables called data and link.)

void list_insert_zero(node* previous_ptr);

// Precondition: previous_ptr is a pointer to a node on a linked list.

// Postcondition: A new node has been added to the list after // the node that previous_ptr points to. The new node contains 0.