| Index: pkg/serialization/lib/src/basic_rule.dart
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| diff --git a/pkg/serialization/lib/src/basic_rule.dart b/pkg/serialization/lib/src/basic_rule.dart
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| index c640ba6ba5113ee4c6a717dbf68abce234852722..b3e3a95a8883170a766803b108885e2369aa898d 100644
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| --- a/pkg/serialization/lib/src/basic_rule.dart
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| +++ b/pkg/serialization/lib/src/basic_rule.dart
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| @@ -419,7 +419,7 @@ class _ConstantField extends _Field {
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|   * are kept in a separate object, which also has the ability to compute the
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|   * default fields to use reflectively.
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|   */
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| -class _FieldList extends Iterable {
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| +class _FieldList extends IterableBase {
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|    /**
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|     * All of our fields, indexed by name. Note that the names are not
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|     * necessarily strings.
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| 
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