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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.math4.legacy.exception.util;
18  
19  import java.util.Arrays;
20  import java.util.List;
21  import java.util.ArrayList;
22  
23  /**
24   * Utility class for transforming the list of arguments passed to
25   * constructors of exceptions.
26   */
27  public final class ArgUtils {
28      /**
29       * Class contains only static methods.
30       */
31      private ArgUtils() {}
32  
33      /**
34       * Transform a multidimensional array into a one-dimensional list.
35       *
36       * @param array Array (possibly multidimensional).
37       * @return a list of all the {@code Object} instances contained in
38       * {@code array}.
39       */
40      public static Object[] flatten(Object[] array) {
41          final List<Object> list = new ArrayList<>();
42          if (array != null) {
43              for (Object o : array) {
44                  if (o instanceof Object[]) {
45                      list.addAll(Arrays.asList(flatten((Object[]) o)));
46                  } else {
47                      list.add(o);
48                  }
49              }
50          }
51          return list.toArray();
52      }
53  }