pub fn insert_at_line(
project: &ProjectRoot,
relative_path: &str,
line: usize,
content_to_insert: &str,
) -> Result<(String, ApplyEvidence)>pub fn insert_at_line(
project: &ProjectRoot,
relative_path: &str,
line: usize,
content_to_insert: &str,
) -> Result<(String, ApplyEvidence)>