Ah found it…functions that accept variable length arguments are called Variadic Functions. Example:
package main
import "fmt"
func MyPrint(format string, args ...interface{}) {
fmt.Printf("[MY PREFIX] " + format, args...)
}
func main() {
MyPrint("yay %d %d\n",123,234);
MyPrint("yay %d\n ",123);
MyPrint("yay %d\n");
}