Function parse_file 

pub fn parse_file(
    config_file: PathBuf,
    id_map: &TreeMap<CString, Vec<TaxonInfo>>,
    write_validated: bool,
    create_taxa: bool,
    xref_label: Option<String>,
    skip_tsv: bool,
) -> Result<(Nodes, HashMap<String, Vec<Name>>, Source), Error>