Example:

nums := [][]int{[]int{1}, []int{2}}

We have a slice of slices of the int type. In this case, you can use a shorter definition. You can fix this code manually or use the Delete redundant type quick-fix. After the quick-fix is applied, the code looks as follows:

nums := [][]int{{1},{2}}

For more information about composite literals, refer to Go Language Specification: Composite Literals at go.dev.