input: Write a python function to calculate the sum of the first 10 prime numbers.
  assert sum_first_10_primes() == 129
  assert sum_first_10_primes() != 130
output: def sum_first_10_primes():
      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
      
      sum_primes = 0
      count = 0
      num = 2
      while count < 10:
          if is_prime(num):
              sum_primes += num
              count += 1
          num += 1
      
      return sum_primes