add nullaway

Author: zeitlinger

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/DbClientCommonAttributesGetter.java

@@ -5,6 +5,8 @@
 
 package io.opentelemetry.instrumentation.api.incubator.semconv.db;
 
+import static java.util.Objects.requireNonNull;
+
 import javax.annotation.Nullable;
 
 /** An interface for getting attributes common to database clients. */
@@ -16,7 +18,12 @@ default String getSystem(REQUEST request) {
     return null;
   }
 
-  String getDbSystem(REQUEST request);
+  // TODO: make this required to implement
+  default String getDbSystem(REQUEST request) {
+    // this method will become abstract in
+    // https://github.com/open-telemetry/opentelemetry-java-instrumentation/pull/14460
+    return requireNonNull(getSystem(request));
+  }
 
   @Deprecated
   @Nullable

instrumentation-api-incubator/src/main/java/io/opentelemetry/instrumentation/api/incubator/semconv/db/SqlClientAttributesGetter.java

@@ -65,6 +65,7 @@ default Collection<String> getRawQueryTexts(REQUEST request) {
   }
 
   // TODO: make this required to implement
+  @Nullable
   default Long getBatchSize(REQUEST request) {
     return null;
   }