Function CFErrorCopyUserInfo 

pub unsafe extern "C" fn CFErrorCopyUserInfo(
    err: CFErrorRef,
) -> CFDictionaryRef

@function CFErrorCopyUserInfo @abstract Returns CFError userInfo dictionary. @discussion Returns a dictionary containing the same keys and values as in the userInfo dictionary the CFError was created with. Returns an empty dictionary if NULL was supplied to CFErrorCreate(). @param err The CFError whose error user info is to be returned. If this reference is not a valid CFError, the behavior is undefined. @result The user info of the CFError.