function populateConstructorExports (exports, codes, HttpError) {
	  codes.forEach(function forEachCode (code) {
	    var CodeError;
	    var name = toIdentifier(statuses.message[code]);

	    switch (codeClass(code)) {
	      case 400:
	        CodeError = createClientErrorConstructor(HttpError, name, code);
	        break
	      case 500:
	        CodeError = createServerErrorConstructor(HttpError, name, code);
	        break
	    }

	    if (CodeError) {
	      // export the constructor
	      exports[code] = CodeError;
	      exports[name] = CodeError;
	    }
	  });
	}
Populate the exports object with constructors for every error class.
@private