code: def rmse_loss(outputs, inputs):
      valid_mask = inputs[dataset_keys.VALID_MASK_IMG]
      gt_depth = inputs[dataset_keys.HIGH_RES_DEPTH_IMG]
      prediction = outputs[dataset_keys.PREDICTION_DEPTH_IMG]
      loss = F.mse_loss(prediction[valid_mask], gt_depth[valid_mask])
      loss = torch.sqrt(loss)
      return loss
  
imports: import torch
  import torch.nn.functional
  import dataset_keys
label_desc: Use image node_id 1 for calling a global function with example usage: rmse_loss(outputs, inputs) and returns: loss