code: public boolean containsKey( Object key )
    {
      int hash = hash( key.hashCode() );
      return segmentFor( hash ).containsKey( key, hash );
    }
docs: Tests if the specified object is a key in this table.
  
  @param key possible key
  
  @return <tt>true</tt> if and only if the specified object
  is a key in this table, as determined by the
  <tt>equals</tt> method; <tt>false</tt> otherwise.
  
  @throws NullPointerException if the specified key is null