logit_bias is of type Option<HashMap<String, String>> in ChatBody

[Lowband21]

When a map of type HashMap<String, String> is passed for logit_bias, the following error results:

Error: API error: {"error":{"code":null,"message":"All values in 'logit_bias' must be reals, but found a <class 'str'>","param":"logit_bias","type":"invalid_request_error"}}. Trying again...

And obviously it won't compile if I try to pass any other type.