虽然在最终的链上 DERO 并不存在孤儿块，但在处理过程中引入相关概念，可以更好的进行理解和处理。

isblock_SideBlock 副块

// side blocks are blocks which lost the race the to become part
// of main chain, but there transactions are honoured,
// they are given 67 % reward
// a block is a side block if it satisfies the following condition
// if  block height   is less than or equal to height of past 8 topographical blocks
// this is part of consensus rule
// this is the topoheight of this block itself

当前，主要影响其对应的挖矿奖励金额。

Is_Block_Orphan 孤儿块

// Finds whether a  block is orphan
// since we donot store any fields, we need to calculate/find the block as orphan
// using an algorithm
// if the block is NOT topo ordered , it is orphan/stale

当前，会将其下面的交易重新放回交易池，回炉重造。

Is_TX_Orphan 孤儿交易

// this is used to find if a tx is orphan, YES orphan TX
// these can occur during  when they are detect to be double-spended on
// so the TX becomes orphan ( chances are less may be less that .000001 % but they are there)
// if a tx is not valid in any of the blocks, it has been mined it is orphan

其实，完全是根据其所在的块进行判断。
当前，此方法没有用到。