import uuid


def train_neural_network(deposit_id: str, max_epoch: int, block_size: float) -> str:
    """
    Starts cross-validation training.

    :param deposit_id: UUID of deposit to train on
    :type deposit_id: str (format: UUID)
    :param max_epoch: max epoch number to train
    :type max_epoch: int
    :param block_size: size of blocks to create (if not found in DB)
    :type block_size: float

    :return: Returns UUID of cross-validation object, which WILL BE created in DB in case of succesfull training
    :rtype: str
    """
    return str(uuid.uuid4())