code: public VpnConnectionInner get(String resourceGroupName, String gatewayName, String connectionName) {
          return getWithServiceResponseAsync(resourceGroupName, gatewayName, connectionName).toBlocking().single().body();
      }
docs: Retrieves the details of a vpn connection.
  
  @param resourceGroupName The resource group name of the VpnGateway.
  @param gatewayName The name of the gateway.
  @param connectionName The name of the vpn connection.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @throws ErrorException thrown if the request is rejected by server
  @throws RuntimeException all other wrapped checked exceptions if the request fails to be sent
  @return the VpnConnectionInner object if successful.