Cleanup

Author: anuraaga

sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/fileconfig/FileConfigUtil.java

@@ -59,10 +59,4 @@ static void requireNullResource(
               + additionalProperties.keySet().stream().collect(joining(",", "[", "]")));
     }
   }
-
-  static void requireNonNullResource(@Nullable Object resource, String resourceName) {
-    if (resource == null) {
-      throw new DeclarativeConfigException(resourceName + " must be set");
-    }
-  }
 }