Merge content of a dict in another

    :param: dict: lhs
      dict where is merged the second one
    :param: dict: rhs
      dict whose content is merged

def merge_dict(lhs, rhs):
    """ Merge content of a dict in another

    :param: dict: lhs
      dict where is merged the second one
    :param: dict: rhs
      dict whose content is merged
    """
    assert isinstance(lhs, dict)
    assert isinstance(rhs, dict)
    for k, v in rhs.iteritems():
        if k not in lhs:
            lhs[k] = v
        else:
            lhs[k] = merge_dict(lhs[k], v)
    return lhs