/// <summary>
/// Returns all keys in this symbol table.
/// To iterate over all of the keys in the symbol table named <tt>st</tt>,
/// use the foreach notation: <tt>for (Key key : st.keys())</tt>.
/// </summary>
/// <returns>all keys in the symbol table</returns>
public IEnumerable <TKey> Keys()
{
return(_st.Keys());
}
/// <summary>
/// Returns all of the keys in this set, as an iterator.
/// To iterate over all of the keys in a set named <tt>set</tt>, use the
/// foreach notation
/// </summary>
/// <returns>an iterator to all of the keys in this set</returns>
public IEnumerator <TKey> Iterator()
{
return(_set.Keys().GetEnumerator());
}