def _getSmartIndenter(indenterName, qpart, indenter):
    """Get indenter by name.
    Available indenters are none, normal, cstyle, haskell, lilypond, lisp, python, ruby, xml
    Indenter name is not case sensitive
    Raise KeyError if not found
    indentText is indentation, which shall be used. i.e. '\t' for tabs, '    ' for 4 space symbols
    """
    indenterName = indenterName.lower()

    if indenterName in ('haskell', 'lilypond'):  # not supported yet
        logger.warning('Smart indentation for %s not supported yet. But you could be a hero who implemented it' % indenterName)
        from qutepart.indenter.base import IndentAlgNormal as indenterClass
    elif 'none' == indenterName:
        from qutepart.indenter.base import IndentAlgBase as indenterClass
    elif 'normal' == indenterName:
        from qutepart.indenter.base import IndentAlgNormal as indenterClass
    elif 'cstyle' == indenterName:
        from qutepart.indenter.cstyle import IndentAlgCStyle as indenterClass
    elif 'python' == indenterName:
        from qutepart.indenter.python import IndentAlgPython as indenterClass
    elif 'ruby' == indenterName:
        from qutepart.indenter.ruby import IndentAlgRuby as indenterClass
    elif 'xml' == indenterName:
        from qutepart.indenter.xmlindent import IndentAlgXml as indenterClass
    elif 'haskell' == indenterName:
        from qutepart.indenter.haskell import IndenterHaskell as indenterClass
    elif 'lilypond' == indenterName:
        from qutepart.indenter.lilypond import IndenterLilypond as indenterClass
    elif 'lisp' == indenterName:
        from qutepart.indenter.lisp import IndentAlgLisp as indenterClass
    elif 'scheme' == indenterName:
        from qutepart.indenter.scheme import IndentAlgScheme as indenterClass
    else:
        raise KeyError("Indenter %s not found" % indenterName)

    return indenterClass(qpart, indenter)
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
                }
            }
        }
    }