https://casablanca.codeplex.com/SourceControl/latest#Release/include/cpprest/http_msg.h
```
class methods
{
public:
#define _METHODS
#define DAT(a,b) _ASYNCRTIMP const static method a; //note that b isn't assigned here!
#include "cpprest/http_constants.dat"
#undef _METHODS
#undef DAT
};
```
The same goes for _HEADER_NAMES
```
class methods
{
public:
#define _METHODS
#define DAT(a,b) _ASYNCRTIMP const static method a; //note that b isn't assigned here!
#include "cpprest/http_constants.dat"
#undef _METHODS
#undef DAT
};
```
The same goes for _HEADER_NAMES