private void deleteImpl(final int startIndex,final int endIndex,final int len){
  System.arraycopy(buffer,endIndex,buffer,startIndex,size - endIndex);
  size-=len;
}

private void deleteImpl ( final int startIndex , final int endIndex , final int len ) { System . arraycopy ( buffer , endIndex , buffer , startIndex , size - endIndex ) ; size -= len ; }
internal method to delete a range without validation .
