% go vet
./structs.go:19:3: struct field _Type has json tag but is not exported
./structs.go:21:4: struct field _Type has json tag but is not exported
./structs.go:29:4: struct field _Type has json tag but is not exported
./structs.go:40:4: struct field _Type has json tag but is not exported
./structs.go:65:4: struct field _Type has json tag but is not exported
./structs.go:81:4: struct field _Type has json tag but is not exported
./structs.go:132:3: struct field _Type has json tag but is not exported
./structs.go:134:4: struct field _Type has json tag but is not exported
./structs.go:142:4: struct field _Type has json tag but is not exported
./structs.go:167:4: struct field _Type has json tag but is not exported
./structs.go:195:3: struct field _Type has json tag but is not exported
./structs.go:198:4: struct field _Type has json tag but is not exported
./structs.go:200:5: struct field _Type has json tag but is not exported
./structs.go:208:5: struct field _Type has json tag but is not exported
./structs.go:233:5: struct field _Type has json tag but is not exported
Before changes: