ifconfigheaders===applicationjson qsstringify

This code block is incomplete and cannot be properly interpreted without additional context. However, based on what is provided, it appears that the code is attempting to check if the value of the 'headers' property in the 'config' object is equal to the string "application/json". If it is, it then attempts to call the 'qs.stringify' function, which would likely be used to serialize and encode an object into a JSON string.