code: def l1_loss(
      input,
      target,
      size_average=None,
      reduce=None,
      reduction="mean",
  ):
      if size_average is not None or reduce is not None:
          reduction = _get_reduction_string(size_average, reduce)
      ret = ivy.l1_loss(input, target, reduction=reduction)
      return ret
  
imports: import ivy
  import ivy.functional.frontends.torch
  from ivy.functional.frontends.torch.func_wrapper import to_ivy_arrays_and_back
  from ivy.func_wrapper import with_unsupported_dtypes, with_supported_dtypes
label_desc: Use image node_id 15 for calling a global function with example usage: l1_loss(input, target, size_average, reduce, reduction) and returns: ret