code: def fetch_namespace():
      
      resp = blockstack.lib.client.get_all_names(hostport=blockstack_indexer_url)
      subdomain_names = blockstack.lib.subdomains.get_all_subdomains()
  
      all_names = list(resp) + list(subdomain_names)
  
      with open(SEARCH_BLOCKCHAIN_DATA_FILE, 'w') as fout:
          fout.write(json.dumps(all_names))
docs: Fetch all names in a namespace that should be indexed.
          Data is saved in data/ directory