code: def exists(val):
      return val is not None
  
file_path: mixture-of-attention/mixture_of_attention/transformer.py
imports: import torch
  import torch.nn.functional
  from torch import nn, einsum
  from einops import rearrange
  from mixture_of_attention.mixture_of_attention import MixtureOfAutoregressiveAttention
  from mixture_of_attention.rotary_emb import RotaryEmbedding
label_desc: Use image node_id 1 for calling a global function with example usage: exists(val) and returns: unknown