Adds a comment to _cbor_builder_append mentioning its invariant
#include "../tags.h"
#include "unicode.h"
+// This function maintains the invariant that no memory reachable by ctx->stack
+// and item would be leaked.
void _cbor_builder_append(cbor_item_t *item,
struct _cbor_decoder_context *ctx) {
if (ctx->stack->size == 0) {
