Data and IdentityCertificate: Make Data::setName virtual so that IdentityCertificate::setName is sure to validate the name.
diff --git a/include/ndn-cpp/data.hpp b/include/ndn-cpp/data.hpp
index d9b8fc1..a99e410 100644
--- a/include/ndn-cpp/data.hpp
+++ b/include/ndn-cpp/data.hpp
@@ -243,59 +243,64 @@
   /**
    * Set the signature to a copy of the given signature.
    * @param signature The signature object which is cloned.
+   * @return This Data so that you can chain calls to update values.
    */
-  void 
+  Data& 
   setSignature(const Signature& signature) 
   { 
     signature_ = signature.clone(); 
     onChanged();
+    return *this;
   }
   
   /**
-   * Set name to a copy of the given Name.
+   * Set name to a copy of the given Name.  This is virtual so that a subclass can override to validate the name.
    * @param name The Name which is copied.
+   * @return This Data so that you can chain calls to update values.
    */
-  void 
-  setName(const Name& name) 
-  { 
-    name_ = name; 
-    onChanged();
-  }
+  virtual Data& 
+  setName(const Name& name);
   
   /**
    * Set metaInfo to a copy of the given MetaInfo.
    * @param metaInfo The MetaInfo which is copied.
+   * @return This Data so that you can chain calls to update values.
    */
-  void 
+  Data& 
   setMetainfo(const MetaInfo& metaInfo) 
   { 
     metaInfo_ = metaInfo; 
     onChanged();
+    return *this;
   }
 
   /**
    * Set the content to a copy of the data in the vector.
    * @param content A vector whose contents are copied.
+   * @return This Data so that you can chain calls to update values.
    */
-  void 
+  Data& 
   setContent(const std::vector<uint8_t>& content) 
   { 
     content_ = content; 
     onChanged();
+    return *this;
   }
   
-  void 
+  Data& 
   setContent(const uint8_t* content, size_t contentLength) 
   { 
     content_ = Blob(content, contentLength); 
     onChanged();
+    return *this;
   }
       
-  void 
+  Data& 
   setContent(const Blob& content) 
   { 
     content_ = content;
     onChanged();
+    return *this;
   }
 
 private:
diff --git a/include/ndn-cpp/security/certificate/identity-certificate.hpp b/include/ndn-cpp/security/certificate/identity-certificate.hpp
index 8cb244d..0319774 100644
--- a/include/ndn-cpp/security/certificate/identity-certificate.hpp
+++ b/include/ndn-cpp/security/certificate/identity-certificate.hpp
@@ -35,7 +35,12 @@
   virtual 
   ~IdentityCertificate();
   
-  Data &
+  /**
+   * Override the base class method to check that the name is a valid identity certificate name.
+   * @param name The identity certificate name which is copied.
+   * @return This Data so that you can chain calls to update values.
+   */
+  virtual Data &
   setName(const Name& name);
 
   virtual Name