Its constructor accepts a Boolean that determines whether a new index is created or whether an existing index is opened.

它的构造函数接收布尔值，确定是否创建新索引，或者打开现有索引。

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In addition to resolving the ambiguity of multiple simple values, specifying an index resolves ambiguity where a constructor has two arguments of the same type.

除了要解析多个简单值的歧义性之外，当构造函数有两个相同类型的的参数时，指定索引可以解决歧义问题。

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