% cat x.go
package p

import "fmt"

func f() {
	x := 1
	for e := range x.Method() {
		switch m := e.(type) {
		case int:
			fmt.Printf("%d\n", m)
		}
	}
}
% go build x.go
# command-line-arguments
./x.go:3:8: "fmt" imported and not used   <<< WRONG
./x.go:7:19: x.Method undefined (type int has no field or method Method)
% gopls check x.go
Log: Loading packages...
Info: Finished loading packages.
Log: Running...
Info: completed
/tmp/x.go: found packages p (x.go) and main (y.go) in /tmp
/tmp/x.go:3:8-13: "fmt" imported and not used   <<< WRONG
/tmp/x.go:7:19-25: x.Method undefined (type int has no field or method Method)
%