def address_balance address
      balance = call_blockchain_api("addressbalance/#{address}")

      raise DogeCoin::InvalidAddress unless is_a_float?(balance)

      balance.to_f
    end
def address_balance address
      balance = call_blockchain_api("addressbalance/#{address}")

      raise DogeCoin::InvalidAddress unless is_a_float?(balance)

      balance.to_f
    end
Returns the address balance (received - sent)
 Raise error if address is invalid