chore: import upstream snapshot with attribution

tests/fixtures/sample.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+    "fmt"
+    "net/http"
+)
+
+type Server struct {
+    port int
+}
+
+func NewServer(port int) *Server {
+    return &Server{port: port}
+}
+
+func (s *Server) Start() error {
+    return http.ListenAndServe(fmt.Sprintf(":%d", s.port), nil)
+}
+
+func (s *Server) Stop() {
+    fmt.Println("stopped")
+}
+
+type Logger interface {
+    Log(msg string)
+}
+
+type Reader interface {
+    Read() string
+}
+
+type ReaderLogger interface {
+    Logger
+    Reader
+}
+
+type BaseProcessor struct{}
+
+type Result struct {
+    value int
+}
+
+type DataProcessor struct {
+    BaseProcessor
+    current *Result
+}
+
+func (d *DataProcessor) Build(input *DataProcessor) (*Result, error) {
+    return nil, nil
+}
+
+func main() {
+    s := NewServer(8080)
+    s.Start()
+}