code: def rpc_get_blockstack_ops_hash_at( self, block_id, **con_info ):
          
          if not check_block(block_id):
              return {'error': 'Invalid block height', 'http_status': 400}
  
          db = get_db_state(self.working_dir)
          ops_hash = db.get_block_ops_hash( block_id )
          db.close()
  
          return self.success_response( {'ops_hash': ops_hash} )
docs: Get the hash over the sequence of names and namespaces altered at the given block.
          Used by SNV clients.
  
          Returns {'status': True, 'ops_hash': ops_hash} on success
          Returns {'error': ...} on error