code: def custom_code(self, mask: str = '@###',
                      char: str = '@', digit: str = '#') -> str:
          
          char_code = ord(char)
          digit_code = ord(digit)
          code = bytearray(len(mask))
  
          def random_int(a: int, b: int) -> int:
              b = b - a
              return int(self.random() * b) + a
  
          _mask = mask.encode()
          for i, p in enumerate(_mask):
              if p == char_code:
                  a = random_int(65, 91)  # A-Z
              elif p == digit_code:
                  a = random_int(48, 58)  # 0-9
              else:
                  a = p
              code[i] = a
          return code.decode()
docs: Generate custom code using ascii uppercase and random integers.
  
          :param mask: Mask of code.
          :param char: Placeholder for characters.
          :param digit: Placeholder for digits.
          :return: Custom code.