I am new in this field and implementing a registration code. But when I search Simple ITK documentation, I find it unfriendly for complete beginners. For example, when I search online to understand the code `sitk.BSplineTransformInitializer(image1 = fixed_slice_img, transformDomainMeshSize = (6,6), order=3)', I don’t get any help. So my question is where I can find proper documentation to know about the parameters (transformDomainMeshSize, order, etc.). What are these values and how can we specify their values. Please elaborate with detail. Thanking you in anticipation.