code: def forward_encoder(self, images, idx_keep=None):
      return self.backbone.encode(images, idx_keep)
  
file_path: lightly/examples/pytorch_lightning_distributed/mae.py
imports: import pytorch_lightning
  import torch
  import torchvision
  from torch import nn
  from lightly.models import utils
  from lightly.models.modules import masked_autoencoder
  from lightly.transforms.mae_transform import MAETransform
label_desc: Use image node_id 2 for calling the MAE obj's underlying member method code with example usage: obj.forward_encoder(images, idx_keep) and returns: self