func (node *ShardBlockNode) GetClosestAncestorAtSlot(slot uint64) *ShardBlockNode {
	n := node.GetAncestorAtSlot(slot)
	if n == nil {
		return node
	}
	return n
}
// GetClosestAncestorAtSlot gets the closest ancestor at or before a certain slot.
GetClosestAncestorAtSlot gets the closest ancestor at or before a certain slot.
// GetClosestAncestorAtSlot gets the closest ancestor at or before a certain slot .
func (node *ShardBlockNode) GetClosestAncestorAtSlot(slot uint64) *ShardBlockNode {
	n := node.GetAncestorAtSlot(slot)
	if n == nil {
		return node
	}
	return n
}
func ( node * ShardBlockNode ) GetClosestAncestorAtSlot ( slot uint64 ) * ShardBlockNode { n := node . GetAncestorAtSlot ( slot ) if n == nil { return node } return n }
GetClosestAncestorAtSlot gets the closest ancestor at or before a certain slot.
GetClosestAncestorAtSlot gets the closest ancestor at or before a certain slot .