| Index: sdk/lib/_collection_dev/arrays.dart
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| diff --git a/sdk/lib/_collection_dev/arrays.dart b/sdk/lib/_collection_dev/arrays.dart
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| index d38240effef850d1dd29ddfa341ad11cf70dafaf..662fa4999e3e9efc589d311c2f92d344bd4197fb 100644
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| --- a/sdk/lib/_collection_dev/arrays.dart
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| +++ b/sdk/lib/_collection_dev/arrays.dart
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| @@ -75,6 +75,15 @@ class Arrays {
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|      return -1;
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|    }
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|  
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| +  static void indicesCheck(List a, int start, int end) {
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| +    if (start < 0 || start > a.length) {
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| +      throw new RangeError.range(start, 0, a.length);
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| +    }
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| +    if (end != null && (end < start || end > a.length)) {
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| +      throw new RangeError.range(end, start, a.length);
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| +    }
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| +  }
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| +
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|    static void rangeCheck(List a, int start, int length) {
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|      if (length < 0) {
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|        throw new ArgumentError("negative length $length");
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| 
 |