func (change *LedgerEntryChange) LedgerKey() LedgerKey {
	switch change.Type {
	case LedgerEntryChangeTypeLedgerEntryCreated:
		change := change.MustCreated()
		return change.LedgerKey()
	case LedgerEntryChangeTypeLedgerEntryRemoved:
		return change.MustRemoved()
	case LedgerEntryChangeTypeLedgerEntryUpdated:
		change := change.MustUpdated()
		return change.LedgerKey()
	case LedgerEntryChangeTypeLedgerEntryState:
		change := change.MustState()
		return change.LedgerKey()
	default:
		panic(fmt.Errorf("Unknown change type: %v", change.Type))
	}
}
func (change *LedgerEntryChange) LedgerKey() LedgerKey {
	switch change.Type {
	case LedgerEntryChangeTypeLedgerEntryCreated:
		change := change.MustCreated()
		return change.LedgerKey()
	case LedgerEntryChangeTypeLedgerEntryRemoved:
		return change.MustRemoved()
	case LedgerEntryChangeTypeLedgerEntryUpdated:
		change := change.MustUpdated()
		return change.LedgerKey()
	case LedgerEntryChangeTypeLedgerEntryState:
		change := change.MustState()
		return change.LedgerKey()
	default:
		panic(fmt.Errorf("Unknown change type: %v", change.Type))
	}
}
// LedgerKey returns the key for the ledger entry that was changed
// in `change`.