22 #ifndef NDN_METADATA_OBJECT_HPP    23 #define NDN_METADATA_OBJECT_HPP    83            optional<uint64_t> version = 
nullopt,
    84            time::milliseconds freshnessPeriod = 10_ms) 
const;
    92     return m_versionedName;
   121   Name m_versionedName;
   126 #endif // NDN_METADATA_OBJECT_HPP 
The interface of signing key management. 
Represents an Interest packet. 
Signing parameters passed to KeyChain. 
#define NDN_CXX_NODISCARD
static const SigningInfo & getDefaultSigningInfo()
Represents an absolute name. 
Represents a Data packet. 
const nullopt_t nullopt((nullopt_t::init()))
Error(const char *expectedType, uint32_t actualType)
represents an error in TLV encoding or decoding