def METHOD_NAME(self):
    scanstring = self.json.decoder.scanstring
    self.assertEqual(
        scanstring('"z\U0001d120x"', 1, True),
        ('z\U0001d120x', 5))
    self.assertEqual(
        scanstring('"\\u007b"', 1, True),
        ('{', 8))
    self.assertEqual(
        scanstring('"A JSON payload should be an object or array, not a string."', 1, True),
        ('A JSON payload should be an object or array, not a string.', 60))
    self.assertEqual(
        scanstring('["Unclosed array"', 2, True),
        ('Unclosed array', 17))
    self.assertEqual(
        scanstring('["extra comma",]', 2, True),
        ('extra comma', 14))
    self.assertEqual(
        scanstring('["double extra comma",,]', 2, True),
        ('double extra comma', 21))
    self.assertEqual(
        scanstring('["Comma after the close"],', 2, True),
        ('Comma after the close', 24))
    self.assertEqual(
        scanstring('["Extra close"]]', 2, True),
        ('Extra close', 14))
    self.assertEqual(
        scanstring('{"Extra comma": true,}', 2, True),
        ('Extra comma', 14))
    self.assertEqual(
        scanstring('{"Extra value after close": true} "misplaced quoted value"', 2, True),
        ('Extra value after close', 26))
    self.assertEqual(
        scanstring('{"Illegal expression": 1 + 2}', 2, True),
        ('Illegal expression', 21))
    self.assertEqual(
        scanstring('{"Illegal invocation": alert()}', 2, True),
        ('Illegal invocation', 21))
    self.assertEqual(
        scanstring('{"Numbers cannot have leading zeroes": 013}', 2, True),
        ('Numbers cannot have leading zeroes', 37))
    self.assertEqual(
        scanstring('{"Numbers cannot be hex": 0x14}', 2, True),
        ('Numbers cannot be hex', 24))
    self.assertEqual(
        scanstring('[[[[[[[[[[[[[[[[[[[["Too deep"]]]]]]]]]]]]]]]]]]]]', 21, True),
        ('Too deep', 30))
    self.assertEqual(
        scanstring('{"Missing colon" null}', 2, True),
        ('Missing colon', 16))
    self.assertEqual(
        scanstring('{"Double colon":: null}', 2, True),
        ('Double colon', 15))
    self.assertEqual(
        scanstring('{"Comma instead of colon", null}', 2, True),
        ('Comma instead of colon', 25))
    self.assertEqual(
        scanstring('["Colon instead of comma": false]', 2, True),
        ('Colon instead of comma', 25))
    self.assertEqual(
        scanstring('["Bad value", truth]', 2, True),
        ('Bad value', 12))