Panic while searching problem with topic

[c0dehu1k]

~/github/leetcode-go main !1 ?8 ❯ leetcode-go topic linkedlist 15s 
▀ Fetcing linkedlist problems... (0s)panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x8 pc=0x7e08dd]

goroutine 1 [running]:
github.com/Manan-Prakash-Singh/leetcode-go/core.GetTopics({0x7ffdafe130cc, 0xa})
/home/om/go/pkg/mod/github.com/!manan-!prakash-!singh/leetcode-go@v0.0.0-20230724185051-b7cb2a476309/core/main.go:193 +0x17d
github.com/Manan-Prakash-Singh/leetcode-go/cmd.glob..func7(0xd3a5c0?, {0xc0000994d0?, 0x1?, 0x1?})
/home/om/go/pkg/mod/github.com/!manan-!prakash-!singh/leetcode-go@v0.0.0-20230724185051-b7cb2a476309/cmd/topic.go:19 +0x2a
github.com/spf13/cobra.(*Command).execute(0xd3a5c0, {0xc0000994a0, 0x1, 0x1})
/home/om/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:944 +0x847
github.com/spf13/cobra.(*Command).ExecuteC(0xd39a40)
/home/om/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:1068 +0x3bd
github.com/spf13/cobra.(*Command).Execute(...)
/home/om/go/pkg/mod/github.com/spf13/cobra@v1.7.0/command.go:992
github.com/Manan-Prakash-Singh/leetcode-go/cmd.Execute()
/home/om/go/pkg/mod/github.com/!manan-!prakash-!singh/leetcode-go@v0.0.0-20230724185051-b7cb2a476309/cmd/root.go:30 +0x2e
main.main()
/home/om/go/pkg/mod/github.com/!manan-!prakash-!singh/leetcode-go@v0.0.0-20230724185051-b7cb2a476309/main.go:9 +0x17