public final boolean at(CharSet charSet,CharSequence csq){
  return index < csq.length() ? charSet.contains(csq.charAt(index)) : false;
}

public final boolean at ( CharSet charSet , CharSequence csq ) { return index < csq . length ( ) ? charSet . contains ( csq . charAt ( index ) ) : false ; }
indicates if this cursor points to any of the specified character in the specified character sequence .
