Function trace_data_flow_in_path 

pub fn trace_data_flow_in_path(
    path: &Path,
    source_var: &str,
    sink_pattern: Option<&str>,
    extensions: Option<&[String]>,
    exclude: Option<&[String]>,
) -> Result<Vec<(String, usize)>, Box<dyn Error>>

Trace data flow across a directory (files matching extensions)