def METHOD_NAME(name, extra_dirs=None):
    global st
    st = getattr(straxen.contexts, name)()
    for sf in st.storage:
        sf.readonly = True
    if extra_dirs is not None:
        for d in extra_dirs:
            if os.access(d, os.W_OK) is not True:
                raise IOError(f'No writing access to {d}. Check mountpoints ')
            st.storage.append(strax.DataDirectory(d, readonly=True))
    st.context_config['allow_incomplete'] = True
    st.context_config['forbid_creation_of'] = (
            '*',
            # In case someone has an old strax that doesn't support * here:
            'raw_records', 'records', 'peaklets',
            'peaks', 'event_basics', 'event_info')