commit 493d99f27fe71cf078563505eede0cf2a3413729
Author: feliperodri <rms.felipe@gmail.com>
Date:   Tue Nov 19 19:01:36 2019 -0400

    Implements __CPROVER_file_local_priority_queue_c_s_swap function
    
    Signed-off-by: feliperodri <rms.felipe@gmail.com>

diff --git a/c/aws-c-common/aws_priority_queue_s_swap_harness.i b/c/aws-c-common/aws_priority_queue_s_swap_harness.i
index cf1021cdd7..30269897bb 100644
--- a/c/aws-c-common/aws_priority_queue_s_swap_harness.i
+++ b/c/aws-c-common/aws_priority_queue_s_swap_harness.i
@@ -8498,7 +8498,18 @@ size_t aws_priority_queue_size(const struct aws_priority_queue *queue) {
 size_t aws_priority_queue_capacity(const struct aws_priority_queue *queue) {
     return aws_array_list_capacity(&queue->container);
 }
-void __CPROVER_file_local_priority_queue_c_s_swap(struct aws_priority_queue *queue, size_t a, size_t b);
+void __CPROVER_file_local_priority_queue_c_s_swap(struct aws_priority_queue *queue, size_t a, size_t b) {
+    __VERIFIER_assert(aws_priority_queue_is_valid(queue));
+    __VERIFIER_assert(a < queue->container.length);
+    __VERIFIER_assert(b < queue->container.length);
+    __VERIFIER_assert(aws_priority_queue_backpointer_index_valid(queue, a));
+    __VERIFIER_assert(aws_priority_queue_backpointer_index_valid(queue, b));
+
+    if (queue->backpointers.data) {
+        __VERIFIER_assert(queue->backpointers.length > a);
+        __VERIFIER_assert(queue->backpointers.length > b);
+    }
+}
 
 void aws_priority_queue_s_swap_harness() {