def install(h, pip, groups, save, save_dev, packages):
    """Install a pip or bower package."""
    if groups:
        groups = [text_type.strip(group) for group in groups.split(",")]
    else:
        groups = h.requirements.keys()

    if not packages:
        for group in groups:
            if group not in h.requirements:
                warning("{} not in requirements".format(group))
                continue
            install = (h.install_bower if group.startswith("bower")
                       else h.install_pip)
            for requirement in h.requirements[group]:
                install(str(requirement), save=False, save_dev=False)
    if pip:
        for package in packages:
            h.install_pip(package, save=save, save_dev=save_dev)
    else:
        for package in packages:
            h.install_bower(package, save=save, save_dev=save_dev)
def get_spec(field, limit=10, query='', query_dsl=''):
    """Returns aggregation specs for a term of filtered events.

    The aggregation spec will summarize values of an attribute
    whose events fall under a filter.

    Args:
        field (str): this denotes the event attribute that is used
            for aggregation.
        limit (int): How many buckets to return, defaults to 10.
        query (str): the query field to run on all documents prior to
            aggregating the results.
        query_dsl (str): the query DSL field to run on all documents prior
            to aggregating the results (optional). Either a query string
            or a query DSL has to be present.

    Raises:
        ValueError: if neither query_string or query_dsl is provided.

    Returns:
        a dict value that can be used as an aggregation spec.
    """
    if query:
        query_filter = {
            'bool': {
                'must': [
                    {
                        'query_string': {
                            'query': query
                        }
                    }
                ]
            }
        }
    elif query_dsl:
        query_filter = query_dsl
    else:
        raise ValueError('Neither query nor query DSL provided.')


    return {
        'query': query_filter,
        'aggs': {
            'aggregation': {
                'terms': {
                    'field': field,
                    'size': limit
                }
            }
        }
    }