code: def check_collapsed_pairs(pairs):
      num_ident = (vector_norm(pairs[:, 0] - pairs[:, 1]) < 1e-9).sum()
      if num_ident:
          raise ValueError(
              "{} collapsed pairs found (where the left element is "
              "the same as the right element), out of {} pairs "
              "in total.".format(num_ident, pairs.shape[0])
          )
  
imports: import numpy
  from numpy.linalg import LinAlgError
  from sklearn.datasets import make_spd_matrix
  from sklearn.decomposition import PCA
  from sklearn.utils import check_array
  from sklearn.utils.validation import check_X_y, check_random_state
  from .exceptions import PreprocessorError, NonPSDError
  from sklearn.discriminant_analysis import LinearDiscriminantAnalysis
  from scipy.linalg import pinvh, eigh
  import sys
  import time
  import warnings
label_desc: Use image node_id 11 for calling a global function with example usage: check_collapsed_pairs(pairs) without return types