:parameter `is_function_abi` is used to distinguish  function abi from contract abi
    Returns a dictionary of the transaction that could be used to call this
    TODO: make this a public API
    TODO: add new prepare_deploy_transaction API

def prepare_transaction(
        address,
        web3,
        fn_identifier,
        contract_abi=None,
        fn_abi=None,
        transaction=None,
        fn_args=None,
        fn_kwargs=None):
    """
    :parameter `is_function_abi` is used to distinguish  function abi from contract abi
    Returns a dictionary of the transaction that could be used to call this
    TODO: make this a public API
    TODO: add new prepare_deploy_transaction API
    """
    if fn_abi is None:
        fn_abi = find_matching_fn_abi(contract_abi, fn_identifier, fn_args, fn_kwargs)

    validate_payable(transaction, fn_abi)

    if transaction is None:
        prepared_transaction = {}
    else:
        prepared_transaction = dict(**transaction)

    if 'data' in prepared_transaction:
        raise ValueError("Transaction parameter may not contain a 'data' key")

    if address:
        prepared_transaction.setdefault('to', address)

    prepared_transaction['data'] = encode_transaction_data(
        web3,
        fn_identifier,
        contract_abi,
        fn_abi,
        fn_args,
        fn_kwargs,
    )
    return prepared_transaction