input: Write a function to create a Python program that prints "Hello World!" five times. If the given input is an integer value greater than 1, the program should print "Hello World!" the number of times specified by the input. If the input is anything else or not provided, the program should print "Hello World!" five times by default.
  assert print_hello_world() == None
  assert print_hello_world(3) == None
  assert print_hello_world("invalid") == None
  assert print_hello_world(0) == None
  assert print_hello_world(-1) == None
output: def print_hello_world(n=None):
      if n is None or not isinstance(n, int) or n <= 0:
          n = 5
      for _ in range(n):
          print("Hello World!")