protected final void expandCapacity(int minimumCapacity){
  int newCapacity=Math.max(2 * _buffer.length,minimumCapacity);
  char[] chars=new char[newCapacity];
  System.arraycopy(buffer(),0,chars,0,_buffer.length);
  _buffer=chars;
}

protected final void expandCapacity ( int minimumCapacity ) { int newCapacity = Math . max ( 2 * _buffer . length , minimumCapacity ) ; char [ ] chars = new char [ newCapacity ] ; System . arraycopy ( buffer ( ) , 0 , chars , 0 , _buffer . length ) ; _buffer = chars ; }
expands the capacity to a new value .
