How to add lowercase field to NSURLRequest header field?

I'm getting pretty frustrated figuring out how to add a lowercase header field to an NSMutableURLRequest.

NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:MyURLString]];
[urlRequest setValue:@"aValue" forHTTPHeaderField:@"field"];

In the 开发者_StackOverflowexample above, "field" gets switched to "Field," since the header field names are case insensitive. I would think this shouldn't happen, but it does. The API I am working with is case sensitive, so my GET request is ignored. Is there any way to override the case switch?

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HTTP header fields are supposed to be case insensitive, so you need to fix your API.

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I have written a blog post on the topic: Fixing -[NSMutableURLRequest setValue:forHTTPHeaderField:] I suggest you to read it. You will learn how to fix this problem and why you should not fix it.

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can u please try with addValue(_:forHTTPHeaderField:)?

NSMutableURLRequest *urlRequest = [NSMutableURLRequest requestWithURL:
[NSURL URLWithString:MyURLString]];
[urlRequest addValue:@"aValue" forHTTPHeaderField:@"field"];