Function s 

pub fn s(v: &Value, key: &str) -> String

What: Extract a string value from a JSON object by key, defaulting to empty string.

Inputs:

• v: JSON value to extract from.
• key: Key to look up in the JSON object.

Output:

• Returns the string value if found, or an empty string if the key is missing or not a string.

Details:

• Returns "" if the key is missing or the value is not a string type.