Added non-const getters for vector members so they can be manipulated directly.
diff --git a/ndn-cpp/publisher-public-key-digest.hpp b/ndn-cpp/publisher-public-key-digest.hpp
index 92c36f5..0926f43 100644
--- a/ndn-cpp/publisher-public-key-digest.hpp
+++ b/ndn-cpp/publisher-public-key-digest.hpp
@@ -46,6 +46,7 @@
   }
 
   const std::vector<unsigned char> &getPublisherPublicKeyDigest() const { return publisherPublicKeyDigest_; }
+  std::vector<unsigned char> &getPublisherPublicKeyDigest() { return publisherPublicKeyDigest_; }
 
   void setPublisherPublicKeyDigest(const std::vector<unsigned char> &publisherPublicKeyDigest) { publisherPublicKeyDigest_ = publisherPublicKeyDigest; }
   void setPublisherPublicKeyDigest(const unsigned char *publisherPublicKeyDigest, unsigned int publisherPublicKeyDigestLength)