diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/visitor/ClassStats.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/visitor/ClassStats.java
index f441fceb1a..2f4ebbfc99 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/visitor/ClassStats.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/oom/visitor/ClassStats.java
@@ -5,17 +5,24 @@
 package net.sourceforge.pmd.lang.java.oom.visitor;
 
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
+import net.sourceforge.pmd.lang.java.ast.QualifiableNode.QualifiedName;
+
 /**
  * Statistics about a class. Gathers information about the contained members and their signatures,
- * subclasses and superclasses.
+ * subclasses and superclasses. This class does not provide methods to operate directly on its
+ * nested classes, but only on itself. To operate on a nested class, retrieve the correct ClassStats
+ * with {@link PackageStats#getClassStats(QualifiedName, boolean)} then use the methods of
+ * ClassStats.
  *
  * @author Clément Fournier
  */
 public class ClassStats {
+
     private Map<OperationSignature, Set<String>> operations = new HashMap<>();
     private Map<FieldSignature, Set<String>> fields = new HashMap<>();
     private Map<String, ClassStats> nestedClasses = new HashMap<>();
@@ -27,8 +34,8 @@ public class ClassStats {
 
 
     /**
-     * Adds a ClassStats to the children of this class. This cannot be a nested class, for that see
-     * {@see PackageStats#getNestedClassStats}
+     * Finds a ClassStats in the direct children of this class. This cannot be a nested class, for
+     * that see {@link PackageStats#getClassStats(QualifiedName, boolean)}.
      *
      * @param className        Name of the nested class.
      * @param createIfNotFound Create ClassStats if missing.
@@ -43,5 +50,32 @@ public class ClassStats {
         return nestedClasses.get(className);
     }
 
+
+    /**
+     * Adds an operation to these stats
+     *
+     * @param qname The qualified name of the operation
+     * @param sig   The signature of the operation
+     */
+    public void addOperation(QualifiedName qname, OperationSignature sig) {
+        if (!operations.containsKey(sig)) {
+            operations.put(sig, new HashSet<String>());
+        }
+        operations.get(sig).add(qname.getOperation());
+    }
+
+    /**
+     * Adds an operation to these stats (not the nested stats!)
+     *
+     * @param name The qualified name of the operation
+     * @param sig  The signature of the operation
+     */
+    public void addField(String name, FieldSignature sig) {
+        if (!fields.containsKey(sig)) {
+            fields.put(sig, new HashSet<String>());
+        }
+        fields.get(sig).add(name);
+    }
+
     //TODO
 }