code: public boolean isVault() throws Exception {
          Address addr = Address.root().add(CORE_SERVICE, VAULT);
          final ModelNode queryNode = createRequest(READ_RESOURCE, addr);
          final ModelNode results = execute(queryNode);
          if (isSuccess(results)) {
              return true;
          }
  
          return false;
      }
docs: Checks to see if there is already a vault configured.
  
  @return true if the vault is already configured
  @throws Exception any error