code: def causal_1d_pattern(attn_size: int) -> torch.Tensor:
      mask = torch.tril(
          torch.ones(attn_size, attn_size, dtype=torch.bool)
      )
      return mask
  
imports: import math
  from typing import List
  import numpy
  import torch
  from xformers.components.attention.sparsity_config import BigBirdSparsityConfig, BSLongformerSparsityConfig, FixedSparsityConfig, VariableSparsityConfig
label_desc: Use image node_id 10 for calling a global function with example usage: causal_1d_pattern(attn_size) and returns: mask