def encode(hex)
      leading_zero_bytes = (hex.match(/^([0]+)/) ? $1 : '').size / 2
      int_val = hex.to_i(16)
      base58_val = ''
      while int_val > 0
        int_val, remainder = int_val.divmod(SIZE)
        base58_val = ALPHABET[remainder] + base58_val
      end
      ('1' * leading_zero_bytes) + base58_val
    end
def encode(hex)
      leading_zero_bytes = (hex.match(/^([0]+)/) ? $1 : '').size / 2
      int_val = hex.to_i(16)
      base58_val = ''
      while int_val > 0
        int_val, remainder = int_val.divmod(SIZE)
        base58_val = ALPHABET[remainder] + base58_val
      end
      ('1' * leading_zero_bytes) + base58_val
    end
encode hex value to base58 string.