Pass custom keywords on iOS

Custom keywords are used to attach arbitrary key-value pairs to the request body of the ad call. These can be used for several purposes, including:

The following line of code adds a single key-value pair to the JSON body of ad the call:

// Add key foo with a single value (bar).
[banner addCustomKeywordWithKey:@"foo" value:@"bar"];

For a more robust/complex setup, you can pass multiple values for the same key in the ad call. To do this, call addCustomKeywordWithKey:(NSString *)key value:(NString *)value multiple times with the same key:

[banner addCustomKeywordWithKey:@"foo" value:@"bar"];
[banner addCustomKeywordWithKey:@"foo" value:@"baz"];
[banner addCustomKeywordWithKey:@"foo" value:@"foe"];
[banner addCustomKeywordWithKey:@"customkey" value:@"bar"];