code: def forward(ctx, src, group, tensor):
      ctx.src = src
      ctx.group = group
      ctx.rank = dist.get_rank()
      # torch.distributed makes all the calls in place
      # we allocate new tensors to avoid this
      tensor = tensor.clone()
      dist.broadcast(tensor, src, group=group)
      return tensor
  
imports: import torch
  import torch.distributed
  from torch.autograd import Function
label_desc: Use image node_id 1 for calling the _Broadcast obj's underlying member method code with example usage: obj.forward(ctx, src, group, tensor) and returns: tensor