go test (use go sdk) twice throw error

[needkane]

cd ann-go-sdk/example

[kane@localhost example]$ go test
PASS
ok github.com/dappledger/ann-go-sdk/example 23.549s
[kane@localhost example]$ go test
--- FAIL: TestKV (6.03s)
za_test.go:156:
Error Trace: za_test.go:156
Error: Expected nil, but got: &errors.errorString{s:"Response error: Error unreflecting result: duplicate key :[107 101 121 49]"}
Test: TestKV
za_test.go:169:
Error Trace: za_test.go:169
Error: Expected nil, but got: &errors.errorString{s:"Response error: Error unreflecting result: duplicate key :[107 101 121 50]"}
Test: TestKV
za_test.go:182:
Error Trace: za_test.go:182
Error: Expected nil, but got: &errors.errorString{s:"Response error: Error unreflecting result: duplicate key :[107 101 121 51]"}
Test: TestKV
za_test.go:204: key2 value2
za_test.go:204: key3 value3
FAIL
exit status 1
FAIL github.com/dappledger/ann-go-sdk/example 20.851s

[wickyyang]

Error has responded "Response error: Error unreflecting result: duplicate key :[107 101 121 51]"