code: def get_first_arg_index(mat: torch.Tensor, label: int) -> int:
      """
      Get the index of the first element are specified by `index` variable.
  
      Args:
          mat (Tensor):
              Source matrix filled with indices
          label (int):
              Label which we want to find the first occuring index
  
      Returns:
          (int): The first index of the given label
      """
      return int(torch.where(mat == label)[0][0])
  
imports: from typing import List, Tuple
  import torch
  from nemo.collections.asr.parts.utils.offline_clustering import NMESC, SpeakerClustering, SpectralClustering, get_scale_interpolated_embs, getAffinityGraphMat, getCosAffinityMatrix, split_input_data
  from nemo.collections.asr.parts.utils.optimization_utils import linear_sum_assignment
label_desc: Use image node_id 9 for calling a global function with example usage: get_first_arg_index(mat, label) and returns: int