Using the list ADT of Figure 4.1, write a function to interchange the current element and the one following it.

/** List ADT */ public interface List { } /** Remove all contents from the list, so it is once again empty. Client is responsible for reclaiming storage used by the list elements. */ public void clear(); /** Insert an element at the current location. The client is responsible for ensuring that the list's capacity is not exceeded. @param item The element to be inserted. */ public void insert (E item); /** Append an element at the end of the list. The client is responsible for ensuring that the list's capacity is not exceeded. @param item The element to be appended. */ public void append (E item); /** Remove and return the current element. @return The element that was removed. */ public E remove (); /** Set the current position to the start of the list */ public void moveToStart (); /** Set the current position to the end of the list */ public void moveToEnd (); /** Move the current position one step left. No change if already at beginning. */ public void prev (); /** Move the current position one step right. No change if already at end. */ public void next (); /** @return The number of elements in the list. */ public int length(); /** @return The position of the current element. */ public int currPos (); /** Set current position. @param pos The position to make current. */ public void moveToPos (int pos); /** @return The current element. */ public E getValue (); Figure 4.1