code: def get_oracle_num_spkrs(rec_id, spkr_info):
      """
      Returns actual number of speakers in a recording from the ground-truth.
      This can be used when the condition is oracle number of speakers.
  
      Arguments
      ---------
      rec_id : str
          Recording ID for which the number of speakers have to be obtained.
      spkr_info : list
          Header of the RTTM file. Starting with `SPKR-INFO`.
  
      Example
      -------
      >>> from speechbrain.processing import diarization as diar
      >>> spkr_info = ['SPKR-INFO ES2011a 0 <NA> <NA> <NA> unknown ES2011a.A <NA> <NA>',
      ... 'SPKR-INFO ES2011a 0 <NA> <NA> <NA> unknown ES2011a.B <NA> <NA>',
      ... 'SPKR-INFO ES2011a 0 <NA> <NA> <NA> unknown ES2011a.C <NA> <NA>',
      ... 'SPKR-INFO ES2011a 0 <NA> <NA> <NA> unknown ES2011a.D <NA> <NA>',
      ... 'SPKR-INFO ES2011b 0 <NA> <NA> <NA> unknown ES2011b.A <NA> <NA>',
      ... 'SPKR-INFO ES2011b 0 <NA> <NA> <NA> unknown ES2011b.B <NA> <NA>',
      ... 'SPKR-INFO ES2011b 0 <NA> <NA> <NA> unknown ES2011b.C <NA> <NA>']
      >>> diar.get_oracle_num_spkrs('ES2011a', spkr_info)
      4
      >>> diar.get_oracle_num_spkrs('ES2011b', spkr_info)
      3
      """
  
      num_spkrs = 0
      for line in spkr_info:
          if rec_id in line:
              # Since rec_id is prefix for each speaker
              num_spkrs += 1
  
      return num_spkrs
  
imports: import csv
  import numbers
  import warnings
  import scipy
  import pytest
  import numpy
  from scipy import sparse
  from scipy.sparse.linalg import eigsh
  from scipy.sparse.csgraph import connected_components
  from scipy.sparse.csgraph import laplacian
label_desc: Use image node_id 13 for calling a global function with example usage: get_oracle_num_spkrs(rec_id, spkr_info) and returns: num_spkrs