input: Write a python function to sum prime numbers up to a given limit.
  assert sum_prime_numbers(10) == 17
  assert sum_prime_numbers(20) == 77
  assert sum_prime_numbers(30) == 129
output: def sum_prime_numbers(limit):
      def is_prime(n):
          if n <= 1:
              return False
          for i in range(2, int(n**0.5) + 1):
              if n % i == 0:
                  return False
          return True
  
      return sum(n for n in range(2, limit + 1) if is_prime(n))