// this is used to print blockheader for the rpc and the daemon
type BlockHeader_Print struct {
    Depth         int64  `json:"depth"`
    Difficulty    string `json:"difficulty"`
    Hash          string `json:"hash"`
    Height        int64  `json:"height"`
    TopoHeight    int64  `json:"topoheight"`
    Major_Version uint64 `json:"major_version"`
    Minor_Version uint64 `json:"minor_version"`
    Nonce         uint64 `json:"nonce"`
    Orphan_Status bool   `json:"orphan_status"`
    SyncBlock     bool   `json:"syncblock"`
    TXCount       int64  `json:"txcount"`

    Reward    uint64   `json:"reward"`
    Tips      []string `json:"tips"`
    Timestamp uint64   `json:"timestamp"`
}

TopoHeight 是按照规则，选出主链，排序，之后得到的从创世区块到当前区块的（唯一）高度。