input: Write a function that takes two input numbers and prints their product. The function should be named `multiply` and should accept two parameters `a` and `b`. Inside the function, calculate the product of `a` and `b` and print the result. 
  
  assert multiply(3, 4) is None
  assert multiply(5, 6) is None
  assert multiply(0, 7) is None
  assert multiply(-2, 8) is None
  assert multiply(-3, -3) is None
output: def multiply(a, b):
      product = a * b
      print(product)