input: Write a python function to generate a prime number between 10000 and 99999.
  assert isinstance(generate_prime(), int)
  assert 10000 <= generate_prime() <= 99999
  assert is_prime(generate_prime())
output: import random
  
  def is_prime(n):
      if n <= 1:
          return False
      if n <= 3:
          return True
      if n % 2 == 0 or n % 3 == 0:
          return False
      i = 5
      while i * i <= n:
          if n % i == 0 or n % (i + 2) == 0:
              return False
          i += 6
      return True
  
  def generate_prime():
      while True:
          num = random.randint(10000, 99999)
          if is_prime(num):
              return num