code: def policy_loss(
      advantages: torch.Tensor, ratio: torch.Tensor, clip_coef: float
  ) -> torch.Tensor:
      pg_loss1 = -advantages * ratio
      pg_loss2 = -advantages * torch.clamp(
          ratio, 1 - clip_coef, 1 + clip_coef
      )
      return torch.max(pg_loss1, pg_loss2).mean()
  
imports: import torch
  import torch.nn.functional
  from torch import Tensor
label_desc: Use image node_id 1 for calling a global function with example usage: policy_loss(advantages, ratio, clip_coef) and returns: torch