def METHOD_NAME(chainId: int, verifyingContract: bytes, member: bytes, joined: int,
                               marketId: bytes, actorType: int, meta: Optional[str]) -> dict:
    """
    :param chainId:
    :param verifyingContract:
    :param member:
    :param joined:
    :param marketId:
    :param actorType:
    :param meta:
    :return:
    """
    assert is_chain_id(chainId)
    assert is_address(verifyingContract)
    assert is_address(member)
    assert is_block_number(joined)
    assert is_bytes16(marketId)
    assert type(actorType) == int
    assert meta is None or type(meta) == str
    data = {
        'types': {
            'EIP712Domain': [
                {
                    'name': 'name',
                    'type': 'string'
                },
                {
                    'name': 'version',
                    'type': 'string'
                },
            ],
            'EIP712MarketJoin': [
                {
                    'name': 'chainId',
                    'type': 'uint256'
                },
                {
                    'name': 'verifyingContract',
                    'type': 'address'
                },
                {
                    'name': 'member',
                    'type': 'address'
                },
                {
                    'name': 'joined',
                    'type': 'uint256'
                },
                {
                    'name': 'marketId',
                    'type': 'bytes16'
                },
                {
                    'name': 'actorType',
                    'type': 'uint8'
                },
                {
                    'name': 'meta',
                    'type': 'string',
                },
            ]
        },
        'primaryType': 'EIP712MarketJoin',
        'domain': {
            'name': 'XBR',
            'version': '1',
        },
        'message': {
            'chainId': chainId,
            'verifyingContract': verifyingContract,
            'member': member,
            'joined': joined,
            'marketId': marketId,
            'actorType': actorType,
            'meta': meta or '',
        }
    }
    return data