pub fn new_version(&mut self, fv: MuID) {
        if self.cur_ver.is_some() {
            let obsolete_ver = self.cur_ver.unwrap();
            self.all_vers.push(obsolete_ver);
        }

        self.cur_ver = Some(fv);
    }
/// adds a new version to this function, and it becomes the current version
adds a new version to this function, and it becomes the current version
adds a new version to this function and it becomes the current version
pub fn new_version(&mut self, fv: MuID) {
        if self.cur_ver.is_some() {
            let obsolete_ver = self.cur_ver.unwrap();
            self.all_vers.push(obsolete_ver);
        }
        self.cur_ver = Some(fv);
    }
pub fn new_version ( & mut self , fv : MuID ) { if self . cur_ver . is_some ( ) { let obsolete_ver = self . cur_ver . unwrap ( ) ; self . all_vers . push ( obsolete_ver ) ; } self . cur_ver = Some ( fv ) ; }
adds a new version to this function, and it becomes the current version
adds a new version to this function and it becomes the current version
&mut self
fv
MuID
&mut self
fv
MuID