code: public VirtualNetworkRuleInner beginCreateOrUpdate(String resourceGroupName, String serverName, String virtualNetworkRuleName, VirtualNetworkRuleInner parameters) {
          return beginCreateOrUpdateWithServiceResponseAsync(resourceGroupName, serverName, virtualNetworkRuleName, parameters).toBlocking().single().body();
      }
docs: Creates or updates an existing virtual network rule.
  
  @param resourceGroupName The name of the resource group that contains the resource. You can obtain this value from the Azure Resource Manager API or the portal.
  @param serverName The name of the server.
  @param virtualNetworkRuleName The name of the virtual network rule.
  @param parameters The requested virtual Network Rule Resource state.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws CloudException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the VirtualNetworkRuleInner object if successful.