fix stubs

Author: am0o0

go/ql/src/experimental/frameworks/DecompressionBombs.qll

@@ -605,31 +605,19 @@ module DecompressionBombs {
         none()
       }
     }
-
-    class TheSink extends Sink {
-      TheSink() {
-        exists(Method m |
-          m.hasQualifiedName("github.com/klauspost/compress/s2", "Reader",
-            ["DecodeConcurrent", "ReadByte", "Read"])
-        |
-          this = m.getACall().getReceiver()
-        )
-      }
-    }
   }
 
   /**
    * Provides decompression bomb sinks and additional flow steps for `github.com/klauspost/compress/s2` package
    */
   module KlauspostS2 {
-    class TheSink extends DataFlow::Node {
+    class TheSink extends Sink {
       TheSink() {
         exists(Method m |
-          m.getType()
-              .getUnderlyingType()
-              .hasQualifiedName("github.com/klauspost/compress/s2", "Reader")
+          m.hasQualifiedName("github.com/klauspost/compress/s2", "Reader",
+            ["DecodeConcurrent", "ReadByte", "Read"])
         |
-          this = m.getACall()
+          this = m.getACall().getReceiver()
         )
       }
     }