code: public String getNamespaceIdAsString()
      {
          if (mNamespaceIdAsString == null)
          {
              mNamespaceIdAsString = Bytes.toHexString(getNamespaceId(), true);
          }
  
          return mNamespaceIdAsString;
      }
docs: Get the 10-byte namespace ID as an upper-case hex string.
  
  @return
  The namespace ID.