def is_const_component(record_component):
    """Determines whether a group or dataset in the HDF5 file is constant.

    Parameters
    ----------
    record_component : h5py.Group or h5py.Dataset

    Returns
    -------
    bool
        True if constant, False otherwise

    References
    ----------
    .. https://github.com/openPMD/openPMD-standard/blob/latest/STANDARD.md,
       section 'Constant Record Components'
    """
    return "value" in record_component.attrs.keys()