Function to_string_pretty 

pub fn to_string_pretty<T>(value: &T) -> Result<String>
where
    T: ?Sized + Serialize,

Serialize the given data structure as a pretty-printed String of JSON.

Equivalent to serde_json::to_string_pretty but with errors extended with serde_path_to_error.

See serde_json::to_string_pretty for more documentation.