强大的谓词，官方文档
https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/Predicates/Articles/pCreating.html#//apple_ref/doc/uid/TP40001793
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强大的谓词，官方文档
https://developer.apple.com/library/ios/#documentation/Cocoa/Conceptual/Predicates/Articles/pCreating.html#//apple_ref/doc/uid/TP40001793 
|