Understanding this class intialization in python

I have this piece of code, part of a Spikingjelly neural network training functionality, which gets some errors on this line after running. I'm not quite experienced in Python, and I don't understand what class initialization type this is.

The class definition and the __init__ looks like this:

class DVS128Gesture(sjds.NeuromorphicDatasetFolder):
    def __init__(
            self,
            root: str,
            train: bool = None,
            data_type: str = 'event',
            frames_number: int = None,
            split_by: str = None,
            duration: int = None,
            custom_integrate_function: Callable = None,
            custom_integrated_frames_dir_name: str = None,
            transform: Optional[Callable] = None,
            target_transform: Optional[Callable] = None,
    ) -> None:

And the intialization:

train_data_loader = torch.utils.data.DataLoader(
    dataset=DVS128Gesture(dataset_dir, train=True, use_frame=True, frames_num=T,
                            split_by=split_by, normalization=normalization),
    batch_size=batch_size,
    shuffle=True,
    num_workers=4,
    drop_last=True,
    pin_memory=True)
test_data_loader = torch.utils.data.DataLoader(
    dataset=DVS128Gesture(dataset_dir, train=False, use_frame=True, frames_num=T,
                            split_by=split_by, normalization=normalization),
    batch_size=batch_size,
    shuffle=False,
    num_workers=4,
    drop_last=False,
    pin_memory=True)

For example, class DVS128Gesture expects:

• A string (root) as the address of the dataset

• A bool (train) variable (which is not our interest right now)

• A string

• An integer value allocated to frames_number

The problem: However, the initialization (at the bottom of the picture) is not according to that sequence; for example, useframe=True is used as the 3rd parameter while the class's 3rd parameter was datatype: str = 'event' .

Questions:

1. Is the problem I mentioned above, really an error by the author? or my misunderstanding of something?

2. What's the meaning of a variable assignment during a class initialization? For example, the 4th parameter of class initialization is written framesnum=T. Why not write 'T' directly? and why it was used framesnum instead of the original frames_number written in class definition?

I traced the mentioned variables the their declaration and classes they were used in and as much as I can understand, there is no other variables with the same name.