def get_met_ids(model):
    """
    This function returns a list of IDs of all metabolites in the model.

    Parameters
    ----------
    model : cobra.core.Model.Model
        A cobra model.

    Returns
    -------
    mets : list
        A list containing all IDs of metabolites in the model.
    """
    mets = []
    for met in model.metabolites:
        mets.append(met.id)
    mets = list(set(mets))
    return mets
