24 #ifndef NDN_CXX_LP_NACK_HEADER_HPP    25 #define NDN_CXX_LP_NACK_HEADER_HPP    65   template<encoding::Tag TAG>
    73   wireDecode(
const Block& wire);
   100 #endif // NDN_CXX_LP_NACK_HEADER_HPP 
Represents a TLV element of NDN packet format. 
NackReason
indicates the reason type of a network NACK 
#define NDN_CXX_DECLARE_WIRE_ENCODE_INSTANTIATIONS(ClassName)
std::ostream & operator<<(std::ostream &os, CachePolicyType policy)
bool isLessSevere(lp::NackReason x, lp::NackReason y)
compare NackReason for severity