meta/bundle.go
func (b *Bundle) changes(target xdr.LedgerKey, maxOp int) (ret []xdr.LedgerEntryChange) {
	for _, change := range b.FeeMeta {
		key := change.LedgerKey()

		if !key.Equals(target) {
			continue
		}

		ret = append(ret, change)
	}

	for i, op := range b.TransactionMeta.MustOperations() {
		if i > maxOp {
			break
		}

		for _, change := range op.Changes {
			key := change.LedgerKey()

			if !key.Equals(target) {
				continue
			}

			ret = append(ret, change)
		}
	}

	return
}
func (b *Bundle) changes(target xdr.LedgerKey, maxOp int) (ret []xdr.LedgerEntryChange) {
	for _, change := range b.FeeMeta {
		key := change.LedgerKey()

		if !key.Equals(target) {
			continue
		}

		ret = append(ret, change)
	}

	for i, op := range b.TransactionMeta.MustOperations() {
		if i > maxOp {
			break
		}

		for _, change := range op.Changes {
			key := change.LedgerKey()

			if !key.Equals(target) {
				continue
			}

			ret = append(ret, change)
		}
	}

	return
}
// changes returns any changes within the bundle that apply to the entry
// identified by `key` that occurred at or before `maxOp`.