[
    {
        "type": "function",
        "name": "isValidSignature",
        "constant": true,
        "stateMutability": "view",
        "payable": false,
        "inputs": [
            {
                "type": "bytes32",
                "name": "_message"
            },
            {
                "type": "bytes",
                "name": "_signature"
            }
        ],
        "outputs": [
            {
                "type": "bool",
                "name": ""
            }
        ]
    }
]