code: def asymmetric_l2_loss(u, tau):
      return torch.mean(torch.abs(tau - (u < 0).float()) * u**2)
  
file_path: PARL/parl/algorithms/torch/iql.py
imports: import copy
  import torch
  import torch.nn
  import parl
  import torch.nn.functional
  from parl.utils.utils import check_model_method
label_desc: Use image node_id 1 for calling a global function with example usage: asymmetric_l2_loss(u, tau) and returns: torch