Add comment noting that a Method or Field might have multiple SourceO…

…rSinkElements

go/ql/lib/semmle/go/dataflow/internal/FlowSummaryImpl.qll

@@ -149,6 +149,9 @@ module SourceSinkInterpretationInput implements
     )
   }
 
+  // Note that due to embedding, which is currently implemented via some Methods
+  // or Fields having multiple qualified names, a given Method or Field is liable
+  // to have more than one SourceOrSinkElement, one for each of the names it claims.
   private newtype TSourceOrSinkElement =
     TMethodEntityElement(Method m, string pkg, string type, boolean subtypes) {
       m.hasQualifiedName(pkg, type, _) and subtypes = [true, false]