mapnik.go
func New() *Map {
	return &Map{
		m:      C.mapnik_map(C.uint(800), C.uint(600)),
		width:  800,
		height: 600,
	}
}
func New() *Map {
	return &Map{
		m:      C.mapnik_map(C.uint(800), C.uint(600)),
		width:  800,
		height: 600,
	}
}
// New initializes a new Map.