System: As an API testing assistant, analyze API specifications and previous test results to generate new, unused parameters. Avoid using any parameters from the previous attempts. Return only the parameter dictionary.
User: API Specification:
URL: http://apis.map.qq.com/ws/distance/v1/matrix
Method: GET
Required Parameters: [{'name': 'key', 'type': 'string', 'description': 'api-key', 'default': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI'}, {'name': 'mode', 'type': 'string', 'description': '计算方式：driving（驾车）、walking（步行）。默认：driving', 'default': 'driving'}, {'name': 'from', 'type': 'string', 'description': '起点坐标，格式：lat，lng;lat，lng...（经度与纬度用英文逗号分隔，坐标间用英文分号分隔）', 'default': '39.12,116.83;30.21,115.43'}, {'name': 'to', 'type': 'string', 'description': '终点坐标，格式：lat，lng;lat，lng...（经度与纬度用英文逗号分隔，坐标间用英文分号分隔）', 'default': ''}]
Optional Parameters: [{'name': 'output', 'type': 'string', 'description': '返回格式', 'default': ''}, {'name': 'callback', 'type': 'string', 'description': 'JSONP方式回调函数', 'default': ''}]
Previous attempts: Initial Attempt 1:
Parameters: {'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'from': '39.12,116.83;30.21,115.43', 'to': '31.23,121.47;32.05,118.78', 'output': 'json', 'callback': 'myCallbackFunction'}
Result: Failed
Analysis: Failed - possible issues: Message from API: Success

Initial Attempt 2:
Parameters: {'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'walking', 'from': '34.05,118.25;40.71,74.00', 'to': '37.77,122.42;34.05,118.24', 'output': 'json', 'callback': 'newCallbackFunction'}
Result: Failed
Analysis: Failed - possible issues: Message from API: Success

Recent Attempt 3:
Parameters: {'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'walking', 'from': '40.73,-73.93;34.05,-118.25', 'to': '37.77,-122.42;30.67,-104.06', 'output': 'xml', 'callback': 'anotherCallbackFunction'}
Result: Failed
Analysis: Failed - possible issues: Message from API: 参数错误，坐标错误

Recent Attempt 4:
Parameters: {'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'from': '51.51,-0.13;48.85,2.35', 'to': '35.68,139.76;37.56,126.98', 'output': 'json', 'callback': 'uniqueCallbackFunction123'}
Result: Failed
Analysis: Failed - possible issues: Message from API: 参数错误，坐标错误

Recent Attempt 5:
Parameters: {'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'from': '34.05,-118.25;40.73,-73.93', 'to': '51.51,0.13;48.85,2.35', 'output': 'json', 'callback': 'newUniqueCallback'}
Result: Failed
Analysis: Failed - possible issues: Message from API: 参数错误，坐标错误

Already used parameters: - {'callback': 'newUniqueCallback', 'from': '34.05,-118.25;40.73,-73.93', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'output': 'json', 'to': '51.51,0.13;48.85,2.35'}
- {'callback': 'myCallbackFunction', 'from': '39.12,116.83;30.21,115.43', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'output': 'json', 'to': '31.23,121.47;32.05,118.78'}
- {'callback': 'anotherCallbackFunction', 'from': '40.73,-73.93;34.05,-118.25', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'walking', 'output': 'xml', 'to': '37.77,-122.42;30.67,-104.06'}
- {'callback': '', 'from': '25.03,121.56;22.54,113.93', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'output': '', 'to': '30.67,104.06;39.91,32.85'}
- {'callback': 'uniqueCallbackFunction123', 'from': '51.51,-0.13;48.85,2.35', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'driving', 'output': 'json', 'to': '35.68,139.76;37.56,126.98'}
- {'callback': 'newCallbackFunction', 'from': '34.05,118.25;40.71,74.00', 'key': '6LDBZ-BF4HK-G2ZJA-ABCNH-3A44S-7OFZI', 'mode': 'walking', 'output': 'json', 'to': '37.77,122.42;34.05,118.24'}

Rules:
1. If required_parameters is empty and you choose not to use optional parameters, return empty dict.
2. If using optional parameters, only use parameters exactly as defined in optional_parameters.
3. Do not create new parameters that are not in the specification.

Generate valid parameters:
Assistant: