Need a working sample for updateFunction @google-cloud/functions

[pashaseliverstov]

Unfortunately, the next auto generated samples do not help https://github.com/googleapis/google-cloud-node/tree/main/packages/google-cloud-functions/samples

I am trying to update environment variables via nodejs package "@google-cloud/functions"

Here is my code:
`const test = require("ava");

test.serial("update google function env variables", async (t) => {
const { FunctionServiceClient } = require("@google-cloud/functions").v2;
const client = new FunctionServiceClient();
const [service] = await client.getFunction({
name: "projects/myproject/locations/us-central1/functions/myfunction",
});
t.truthy(service);
service.serviceConfig.environmentVariables["TEST"] = "test";
console.info(service);
const result = await client.updateFunction({
function: service,
updateMask: { paths: ["service_config.environment_variables"] },
});
console.info(result);
t.truthy(result);
});`

The call starts the update but it does not update actual value for serviceConfig.environmentVariables["TEST"]

Please advise