Java tutorial
/* * * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * */ package org.apache.metron.statistics.sampling; import com.google.common.collect.Iterables; import java.util.Optional; public enum SamplerUtil { INSTANCE; public Sampler merge(Iterable<Sampler> samplers, Optional<Sampler> baseSampler) { if (Iterables.isEmpty(samplers)) { return null; } Sampler ret = baseSampler.orElse(Iterables.getFirst(samplers, null).cloneEmpty()); for (Sampler s : samplers) { ret.addAll(s.get()); } return ret; } }