def update(dest, upd, recursive_update=True, merge_lists=False):
    '''
    Recursive version of the default dict.update

    Merges upd recursively into dest

    If recursive_update=False, will use the classic dict.update, or fall back
    on a manual merge (helpful for non-dict types like FunctionWrapper)

    If merge_lists=True, will aggregate list object types instead of replace.
    This behavior is only activated when recursive_update=True. By default
    merge_lists=False.
    '''
    if (not isinstance(dest, collections.Mapping)) \
            or (not isinstance(upd, collections.Mapping)):
        raise TypeError('Cannot update using non-dict types in dictupdate.update()')
    updkeys = list(upd.keys())
    if not set(list(dest.keys())) & set(updkeys):
        recursive_update = False
    if recursive_update:
        for key in updkeys:
            val = upd[key]
            try:
                dest_subkey = dest.get(key, None)
            except __HOLE__:
                dest_subkey = None
            if isinstance(dest_subkey, collections.Mapping) \
                    and isinstance(val, collections.Mapping):
                ret = update(dest_subkey, val, merge_lists=merge_lists)
                dest[key] = ret
            elif isinstance(dest_subkey, list) \
                     and isinstance(val, list):
                if merge_lists:
                    dest[key] = dest.get(key, []) + val
                else:
                    dest[key] = upd[key]
            else:
                dest[key] = upd[key]
        return dest
    else:
        try:
            dest.update(upd)
        except AttributeError:
            # this mapping is not a dict
            for k in upd:
                dest[k] = upd[k]
        return dest
dataset/ETHPy150Open saltstack/salt/salt/utils/dictupdate.py/update