[523] | 1 | package de.ugoe.cs.quest.testgeneration; |
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| 2 | |
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| 3 | import java.security.InvalidParameterException; |
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| 4 | import java.util.ArrayList; |
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| 5 | import java.util.Collection; |
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| 6 | import java.util.HashSet; |
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| 7 | import java.util.LinkedHashSet; |
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| 8 | import java.util.LinkedList; |
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| 9 | import java.util.List; |
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| 10 | import java.util.Random; |
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| 11 | import java.util.Set; |
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[639] | 12 | import java.util.logging.Level; |
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[523] | 13 | |
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| 14 | import de.ugoe.cs.quest.eventcore.Event; |
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| 15 | import de.ugoe.cs.quest.usageprofiles.IStochasticProcess; |
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| 16 | import de.ugoe.cs.util.console.Console; |
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| 17 | |
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| 18 | /** |
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| 19 | * <p> |
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[559] | 20 | * Generates a test suite by drawing from all possible sequences of a fixed length according to the |
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| 21 | * probabilities of the sequences in a {@link IStochasticProcess}. |
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[523] | 22 | * </p> |
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| 23 | * |
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| 24 | * @author Steffen Herbold |
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| 25 | * @version 1.0 |
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| 26 | */ |
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| 27 | public class DrawFromAllSequencesGenerator { |
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| 28 | |
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[559] | 29 | /** |
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| 30 | * <p> |
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| 31 | * Number of sequences in the test suite. |
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| 32 | * </p> |
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| 33 | */ |
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| 34 | private final int numSequences; |
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[523] | 35 | |
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[559] | 36 | /** |
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| 37 | * <p> |
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| 38 | * Minimal length of a test sequence. |
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| 39 | * </p> |
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| 40 | */ |
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| 41 | private final int minLength; |
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[523] | 42 | |
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[559] | 43 | /** |
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| 44 | * <p> |
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| 45 | * Maximal length of a test sequence. |
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| 46 | * </p> |
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| 47 | */ |
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| 48 | private final int maxLength; |
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[523] | 49 | |
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[559] | 50 | /** |
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| 51 | * <p> |
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| 52 | * In case this member is true, only test cases that end in the global end event |
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| 53 | * {@link Event#ENDEVENT} are generated. If it is false, the end event can be any event. |
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| 54 | * </p> |
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| 55 | */ |
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| 56 | private final boolean validEnd; |
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[523] | 57 | |
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[559] | 58 | /** |
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| 59 | * <p> |
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| 60 | * If this member is true, the generated test suite contains all possible sequences and |
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| 61 | * {@link #numSequences} is ignored. |
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| 62 | * </p> |
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| 63 | */ |
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| 64 | private final boolean generateAll; |
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[523] | 65 | |
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[559] | 66 | /** |
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| 67 | * <p> |
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| 68 | * Constructor. Creates a new DrawFromAllSequencesGenerator and ensures the validity of the |
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| 69 | * parameters: |
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| 70 | * <ul> |
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| 71 | * <li>numSequences must at least be 1 |
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| 72 | * <li>maxLength must at least be 1 |
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| 73 | * <li>minLength must be less than or equal to maxLength |
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| 74 | * </ul> |
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| 75 | * If one of these conditions is violated an {@link InvalidParameterException} is thrown. |
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| 76 | * </p> |
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| 77 | * |
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| 78 | * @param numSequences |
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| 79 | * number of sequences desired for the test suite |
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| 80 | * @param minLength |
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| 81 | * minimal length of a test sequence |
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| 82 | * @param maxLength |
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| 83 | * maximal length of a test sequence |
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| 84 | * @param validEnd |
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| 85 | * defines if test cases have to end with the global end event {@link Event#ENDEVENT} |
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| 86 | * (see {@link #validEnd}) |
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| 87 | * @param generateAll |
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| 88 | * if this parameter is true, the test suite contains all possible sequences and |
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| 89 | * numSequences is ignored |
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| 90 | */ |
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| 91 | public DrawFromAllSequencesGenerator(int numSequences, |
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| 92 | int minLength, |
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| 93 | int maxLength, |
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| 94 | boolean validEnd, |
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| 95 | boolean generateAll) |
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| 96 | { |
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| 97 | // check validity of the parameters |
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| 98 | if (numSequences < 1) { |
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| 99 | throw new InvalidParameterException("number of sequences must be at least 1 but is " + |
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| 100 | numSequences); |
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| 101 | } |
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| 102 | if (maxLength < 1) { |
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| 103 | throw new InvalidParameterException( |
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| 104 | "maximal allowed length of test cases must be at least 1 but is " + |
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| 105 | maxLength); |
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| 106 | } |
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| 107 | if (minLength > maxLength) { |
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| 108 | throw new InvalidParameterException( |
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| 109 | "minimal allowed length of test cases must be less than or equal to the maximal allowed length (min length: " + |
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| 110 | minLength + " ; max length: " + maxLength + ")"); |
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| 111 | } |
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| 112 | this.numSequences = numSequences; |
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| 113 | this.minLength = minLength; |
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| 114 | this.maxLength = maxLength; |
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| 115 | this.validEnd = validEnd; |
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| 116 | this.generateAll = generateAll; |
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| 117 | } |
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[523] | 118 | |
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[559] | 119 | /** |
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| 120 | * <p> |
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| 121 | * Generates a test suite by drawing from all possible sequences with valid lengths. |
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| 122 | * </p> |
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| 123 | * |
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| 124 | * @param model |
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| 125 | * model used to determine the probability of each possible sequence |
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| 126 | * @return the test suite |
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| 127 | */ |
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| 128 | public Collection<List<Event>> generateTestSuite(IStochasticProcess model) { |
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| 129 | if (model == null) { |
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| 130 | throw new InvalidParameterException("model must not be null!"); |
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| 131 | } |
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[523] | 132 | |
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[559] | 133 | Collection<List<Event>> sequences = new LinkedHashSet<List<Event>>(); |
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| 134 | for (int length = minLength; length <= maxLength; length++) { |
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| 135 | if (validEnd) { |
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| 136 | sequences.addAll(model.generateValidSequences(length + 2)); |
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| 137 | } |
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| 138 | else { |
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| 139 | sequences.addAll(model.generateSequences(length + 1, true)); |
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| 140 | } |
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| 141 | } |
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[639] | 142 | Console.traceln(Level.INFO, "" + sequences.size() + " possible"); |
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[559] | 143 | if (!generateAll && numSequences < sequences.size()) { |
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| 144 | List<Double> probabilities = new ArrayList<Double>(sequences.size()); |
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| 145 | double probSum = 0.0; |
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| 146 | for (List<Event> sequence : sequences) { |
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| 147 | double prob = model.getProbability(sequence); |
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| 148 | probabilities.add(prob); |
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| 149 | probSum += prob; |
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| 150 | } |
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| 151 | Set<Integer> drawnSequences = new HashSet<Integer>(numSequences); |
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| 152 | Random r = new Random(); |
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| 153 | while (drawnSequences.size() < numSequences) { |
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| 154 | double randVal = r.nextDouble() * probSum; |
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| 155 | double sum = 0.0d; |
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| 156 | int index = -1; |
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| 157 | while (sum < randVal) { |
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| 158 | index++; |
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| 159 | double currentProb = probabilities.get(index); |
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| 160 | sum += currentProb; |
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| 161 | } |
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| 162 | if (!drawnSequences.contains(index)) { |
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| 163 | drawnSequences.add(index); |
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| 164 | probSum -= probabilities.get(index); |
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| 165 | probabilities.set(index, 0.0d); |
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| 166 | } |
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| 167 | } |
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| 168 | Collection<List<Event>> retainedSequences = new LinkedList<List<Event>>(); |
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| 169 | int index = 0; |
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| 170 | for (List<Event> sequence : sequences) { |
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| 171 | if (drawnSequences.contains(index)) { |
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| 172 | retainedSequences.add(sequence); |
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| 173 | } |
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| 174 | index++; |
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| 175 | } |
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| 176 | sequences = retainedSequences; |
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| 177 | } |
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| 178 | return sequences; |
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| 179 | } |
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[523] | 180 | |
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| 181 | } |
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