docs: def get_belns_handle(client, username=None, password=None):
      """Get BEL namespace arango db handle"""
  
      (username, password) = get_user_creds(username, password)
  
      sys_db = client.db("_system", username=username, password=password)
  
      # Create a new database named "belns"
      try:
          if username and password:
              belns_db = sys_db.create_database(
                  name=belns_db_name,
                  users=[{"username": username, "password": password, "active": True}],
              )
          else:
              belns_db = sys_db.create_database(name=belns_db_name)
      except arango.exceptions.DatabaseCreateError:
          if username and password:
              belns_db = client.db(belns_db_name, username=username, password=password)
          else:
              belns_db = client.db(belns_db_name)
  
      try:
          belns_db.create_collection(belns_metadata_name)
      except Exception:
          pass
  
      try:
          equiv_nodes = belns_db.create_collection(
              equiv_nodes_name, index_bucket_count=64
          )
          equiv_nodes.add_hash_index(fields=["name"], unique=True)
      except Exception:
          pass
  
      try:
          belns_db.create_collection(equiv_edges_name, edge=True, index_bucket_count=64)
      except Exception:
          pass
  
      try:
          ortholog_nodes = belns_db.create_collection(
              ortholog_nodes_name, index_bucket_count=64
          )
          ortholog_nodes.add_hash_index(fields=["name"], unique=True)
      except Exception:
          pass
  
      try:
          belns_db.create_collection(
              ortholog_edges_name, edge=True, index_bucket_count=64
          )
      except Exception:
          pass
  
      return belns_db