def get_sample_nwb_metadata(experiment_id):
    """
    Returns sample NWB metadata for testing purposes without needing an ElabFTW token.

    :param experiment_id: Ignored - this function always returns the same sample metadata

    :return: Sample NWB metadata
    :rtype: dict
    """

    # Output of get_nwb_metadata(156) with a valid elabftw token.
    # Note: this needs to be updated when this output changes.
    return {
        "NWBFile": {
            "session_description": "test fake experiment with json metadata",
            "identifier": "20211001-8b6f100d66f4312d539c52620f79d6a503c1e2d1",
            "session_start_time": "2021-10-01 11:13:47",
            "experimenter": ["Liam Keegan"],
            "institution": "Heidelberg University, Physiology and Pathophysiology",
            "lab": "Medical Biophysics, Groh/Mease",
            "virus": "AAVretr ChR2-tdTomato:\n  * Virus in -80 storage: AAVrg-CAG-hChR2-tdTomato (AAV Retrograde)\n  * Origin: Addgene\n  * Comments: retrograde\n  * Expression Quality: \n  * product number: \nAAVretr Flpo:\n  * Virus in -80 storage: AAVretr EF1a-Flpo\n  * Origin: Addgene\n  * Comments: retrograde Flip\n  * Expression Quality: \n  * product number: 55637-AAVrg\n",
        },
        "Subject": {
            "sex": "unknown",
            "weight": 0.002,
            "genotype": "Nt1Cre-ChR2-EYFP",
            "subject_id": "xy1",
            "description": "test mouse",
            "date_of_birth": "2000-01-01",
        },
        "Ecephys": {},
        "Other": {
            "OptogeneticStimulationSite": {
                "device": "the device",
                "location": "S1: primary somatosensory cortex",
                "description": "laser stimulation",
                "excitation_lambda": "473",
            },
            "SiliconProbe": {
                "Probe identifier:": "1234356",
                "ElectrodeGroup.name": "H5",
                "ElectrodeGroup.description": "a test H5 probe",
            },
        },
    }