import java.util.Enumeration;
import java.util.NoSuchElementException;

public class StringIterator {
    public StringIterator (/*@non_null@*/ Enumeration e)
       //@requires e.elementType == \type(String) ;
       //@requires e.returnsNull == false ; 
       // effects: Constructs an iterator that will yield each String in e in order.
    { }
    
    public boolean hasNext ()
        // effects: Returns true iff there are more elements to yield.  
    { }

    public /*@non_null@*/ String next () throws NoSuchElementException 
       // modifies: this
       // effects: If there are more results to yield, returns the next String and
       //    modifies the state of this to record the yield.  Otherwise, throws
       //    NoSuchElementException.
    { }
}