def METHOD_NAME(self) -> bytes:
    '''serializes a node'''
    buf = b''
    buf += self.hashSubtreeCommitment
    buf += struct.pack("<I", self.nEarliestTimestamp)
    buf += struct.pack("<I", self.nLatestTimestamp)
    buf += struct.pack("<I", self.nEarliestTargetBits)
    buf += struct.pack("<I", self.nLatestTargetBits)
    buf += self.hashEarliestSaplingRoot
    buf += self.hashLatestSaplingRoot
    buf += ser_uint256(self.nSubTreeTotalWork)
    buf += ser_compactsize(self.nEarliestHeight)
    buf += ser_compactsize(self.nLatestHeight)
    buf += ser_compactsize(self.nSaplingTxCount)
    if self.hashEarliestOrchardRoot is not None:
        buf += self.hashEarliestOrchardRoot
        buf += self.hashLatestOrchardRoot
        buf += ser_compactsize(self.nOrchardTxCount)
    return buf