How to use the reprozip.reprozip.tracer.trace.TracedFile.ONLY_READ function in reprozip

fp = TracedFile(r_name.parent)
                fp.read(run)
                files[fp.path] = fp

        # Identifies input files
        if r_name.is_file() and r_name not in executed:
            access_files[-1].add(f)
    cur.close()

    # Further filters input files
    inputs = [[fi.path
               for fi in lst
               # Input files are regular files,
               if fi.path.is_file() and
               # ONLY_READ,
               fi.runs[r] == TracedFile.ONLY_READ and
               # not executable,
               # FIXME : currently disabled; only remove executed files
               # not fi.path.stat().st_mode & 0b111 and
               fi.path not in executed and
               # not in a system directory
               not any(fi.path.lies_under(m)
                       for m in magic_dirs + system_dirs)]
              for r, lst in enumerate(access_files)]

    # Identify output files
    outputs = [[fi.path
                for fi in lst
                # Output files are regular files,
                if fi.path.is_file() and
                # WRITTEN
                fi.runs[r] == TracedFile.WRITTEN and

def read(self, run):
        if self.what is None:
            self.what = TracedFile.ONLY_READ

        if run is not None:
            if self.runs[run] is None:
                self.runs[run] = TracedFile.ONLY_READ

def read(self, run):
        if self.what is None:
            self.what = TracedFile.ONLY_READ

        if run is not None:
            if self.runs[run] is None:
                self.runs[run] = TracedFile.ONLY_READ

def read(self, run):
        if self.what is None:
            self.what = TracedFile.ONLY_READ

        if run is not None:
            if self.runs[run] is None:
                self.runs[run] = TracedFile.ONLY_READ