input: Write a function to generate a random 6-digit number in Python. The function should return the generated number as an integer.
  
  assert generate_6_digit_number()==572418
  assert generate_6_digit_number()==123456
  assert generate_6_digit_number()==987654
  assert generate_6_digit_number()==345678
  assert generate_6_digit_number()==234567
output: import random
  
  def generate_6_digit_number():
      return random.randint(100000, 999999)