def concatenate_raws(raws, preload=None):
    """Concatenate raw instances as if they were continuous. Note that raws[0]
    is modified in-place to achieve the concatenation.

    Parameters
    ----------
    raws : list
        list of Raw instances to concatenate (in order).

    preload : bool, or None
        If None, preload status is inferred using the preload status of the
        raw files passed in. True or False sets the resulting raw file to
        have or not have data preloaded.

    Returns
    -------
    raw : instance of Raw
        The result of the concatenation (first Raw instance passed in).
    """
    raws[0].append(raws[1:], preload)
    return raws[0]