private static Long getAggregateCount(Collection<ExecutionsTimerValues> values) {
    return values.stream().map(x -> x.count).reduce(0L, Long::sum);
  }
Acceptance tests for function executions timer on cluster with two servers and one locator
geode-assembly/src/acceptanceTest/java/org/apache/geode/metrics/function/executions/FunctionExecutionsTimerClusterTest.java