test case: "timestamp check without params"
test case: "timestamp check with empty params"
key: "system.localtime[]"
test case: "timestamp check with UTC type param"
key: "system.localtime[utc]"
test case: "localtime check"
timestamp: "2017-12-18,14:06:09.123,+02:30"
key: "system.localtime[local]"
result: "2017-12-18,14:06:09.123,+02:30"
test case: "input parameter count check"
key: "system.localtime[1,2]"
result: "Too many parameters."
return: "SYSINFO_RET_FAIL"
test case: "input parameter value check"
key: "system.localtime[bebebe]"
result: "Invalid first parameter."
return: "SYSINFO_RET_FAIL"