class_docstr: Decoder for :class:`~ffcv.fields.RGBImageField` that performs a center crop operation.
  
  It supports both variable and constant resolution datasets.
  
  Differently from the original CenterCropRGBImageDecoder from FFCV,
  this operates like torchvision CenterCrop.
code: def get_crop_generator(self):
      return get_center_crop_torchvision_alike
  
file_path: avalanche/avalanche/benchmarks/utils/ffcv_support/center_crop.py
imports: from typing import Callable, Tuple
  from ffcv.fields.decoders import SimpleRGBImageDecoder
  from ffcv.pipeline.state import State
  from ffcv.pipeline.allocation_query import AllocationQuery
  import numpy
  from dataclasses import replace
  from ffcv.fields.rgb_image import IMAGE_MODES
  from ffcv.pipeline.compiler import Compiler
  from ffcv.libffcv import imdecode
label_desc: Use image node_id 4 for calling the CenterCropRGBImageDecoderTVAlike obj's underlying member method code with example usage: obj.get_crop_generator() and returns: get_center_crop_torchvision_alike