code: def prepare_input(self, image):
      prev_mask = None
      prev_mask = image[:, 3:, :, :]
      image = image[:, :3, :, :]
      image = self.normalization(image)
      return image, prev_mask
  
imports: import paddle
  import paddle.nn.functional
  import numpy
  from inference.transforms import AddHorizontalFlip, SigmoidForPred, LimitLongestSide
  from .ops import DistMaps, ScaleLayer, BatchImageNormalize
label_desc: Use image node_id 5 for calling the BasePredictor obj's underlying member method code with example usage: obj.prepare_input(image) and returns: image,  prev_mask