code: def add(self, key, skip_check=False):
          
          bitarray = self.bitarray
          bits_per_slice = self.bits_per_slice
          hashes = self.make_hashes(key)
          found_all_bits = True
          if self.count > self.capacity:
              raise IndexError("BloomFilter is at capacity")
          offset = 0
          for k in hashes:
              if not skip_check and found_all_bits and not bitarray[offset + k]:
                  found_all_bits = False
              self.bitarray[offset + k] = True
              offset += bits_per_slice
  
          if skip_check:
              self.count += 1
              return False
          elif not found_all_bits:
              self.count += 1
              return False
          else:
              return True
docs: Adds a key to this bloom filter. If the key already exists in this
          filter it will return True. Otherwise False.
  
          >>> b = BloomFilter(capacity=100)
          >>> b.add("hello")
          False
          >>> b.add("hello")
          True
          >>> b.count
          1