trying to find out what I dont understand

scratch.c

@@ -0,0 +1,43 @@
+#define ALLOCATOR_IMPLEMENTATION
+#include "cig.h"
+#include <stdio.h>
+#include <assert.h>
+
+int main() {
+	// test 1///////////////////////////////////////////////////////////////////////
+    arena_allocator_t aalloc = arena_allocator_create();
+
+    for ( int i = 0; i < 10; i++ ) with_arena(&aalloc, allocator) {
+        allocator_alloc(allocator, 10);
+    }
+
+    assert(aalloc.total_allocated == 10);
+    assert(borrow_allocator_count_allocations(&aalloc.borrow_allocator) == 0);
+    assert(dyn_array_capacity(aalloc.bytes) == 10);
+
+    arena_allocator_destroy(&aalloc);
+    assert(aalloc.total_allocated == 0);
+	arena_allocator_destroy(&aalloc);
+
+	// test 2 //////////////////////////////////////////////////////////////////////
+    aalloc = arena_allocator_create();
+
+    for ( int i = 0; i < 10; i++ ) with_arena(&aalloc, allocator) {
+        allocator_alloc(allocator, 1000);
+    }
+
+	with_arena(&aalloc, allocator) {
+		size_t prev_addr = 0;
+		prev_addr = ~prev_addr;
+		for (int i = 0; i < 1001; i++) {
+			size_t addr = (size_t)allocator_alloc(allocator, 1);
+			assert(addr != prev_addr);
+			assert(addr % MAX_ALIGN == 0);
+		}
+	}
+	arena_allocator_reset(&aalloc);
+	fprintf(stderr, "%zu\n", aalloc.total_allocated);
+    //assert(aalloc.total_allocated == MAX_ALIGN *  1000 + 1);
+	// TODO: WHAT is happening here?
+	arena_allocator_destroy(&aalloc);
+}