How to deal with json string?

[lh12565]

Hi, I have a json string not a json file. How can I resolve the json string? There is an error if run the code as follows:

d3.queue()
    .defer(d3.json, 'data/hg38.json')
    .defer(d3.csv, 'data/cytobands.csv')
    // .defer(d3.csv, 'data/fusion-genes.csv')
    .defer(d3.json, [{
        "source_id": "chr19",
        "source_breakpoint": "24186054",
        "target_id": "chr17",
        "target_breakpoint": "33478117",
        "source_label": "5_8S_rRNA.4",
        "target_label": "UNC45B"
    }])
    .await(drawCircos)

Thanks!