I am writing a simple Python program with some functions, one of which is a `main()` function executes the other functions. However when I run the code below there is no output. Can someone tell me if they see an error in the structure?

```
def print1():
    print("this is also a function")
def print2():
    print("this is a function")

def main():
    print1()
    print2()

```