Groups the elements of a sequence according to a specified key selector function and creates a result value from each group and its key.

依据指定的索引键选择器函式来群组序列的项目，并从每个群组及其索引键建立结果值。

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Rules with a tag selector as the key.

标签选择器作为键的规则。

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The engine evaluates each rule from right to left, starting from the rightmost selector (called the "key") and moving through each selector until it finds a match or discards the rule.

该引擎由右至左评估每个规则，从最右边的选择器开始(称为“键”【Key】)，并通过移动每个选择器，直到找到一个匹配或丢弃的规则。

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National selector Geoff Miller admitted Key's captaincy credentials had been discussed before Collingwood was handed the role.

BBC: Collingwood accepts T20 captaincy