{
    "facets": [ 
        {
            "field": "subject",
            "terms": { 
                "duo-music": 2,
                "orchestra-music": 2,
                "quartet-music": 2,
                "string quartet-music": 2,
                "trio-music": 2,
                "wind ensmeble-music": 2
            }
        },
        {
            "field": "creator",
            "terms": { 
                "han, ziang": 12
            }
        },
        {
            "field": "format",
            "terms": { 
                "application/pdf": 6,
                "audio/mp3": 6
            }
        }
        
    ]
}