hash_destroy on the hash table allocated with TopMemoryContext

I was looking for a pattern to destroy a hashtable (dynahash).allocated in TopMemoryContext 
I found one pattern : create_seq_hashtable uses TopMemoryContext

 memory context to create hash table. It calls hash_destroy in

 ResetSequenceCaches. hash_destroy will destroy the memory context(TopMemoryContext). Is it the right way to use hash_destroy ?

I have allocated a hash table in TopMemoryContext context and I want 

to destroy it. It seems to me that there is no function to destroy hash 

table allocated in TopMemoryContext context.  

-- Sharique