public UnicodeSet clear(){
  list[0]=HIGH;
  len=1;
  pat=null;
  strings.clear();
  return this;
}

public UnicodeSet clear ( ) { list [ 0 ] = HIGH ; len = 1 ; pat = null ; strings . clear ( ) ; return this ; }
removes all of the elements from this set . this set will be empty after this call returns .
