input: Write a function to print a pattern of asterisks in a symmetric pyramid form, with the top half gradually increasing in size and the bottom half gradually decreasing in size. The pattern should be printed in the console. If the input is not provided, the pattern should be generated with a default size of 5.
  assert print_pattern(5)
output: def print_pattern(n=5):
      for i in range(1, n + 1):
          print('*' * i)
      for i in range(n - 1, 0, -1):
          print('*' * i)