class_docstr: Callable probe for early stopping in GroupSparseCovarianceCV.
  
  Stop optimizing as soon as the score on the test set starts decreasing.
  An instance of this class is supposed to be passed in the probe_function
  argument of group_sparse_covariance().
class_docstr_tok: ["Callable","probe","for","early","stopping","in","GroupSparseCovarianceCV",".","Stop","optimizing","as","soon","as","the","score","on","the","test","set","starts","decreasing",".","An","instance","of","this","class","is","supposed","to","be","passed","in","the","probe_function","argument","of","group_sparse_covariance","(",")","."]
code: def __init__(self, test_subjs, verbose=0):
      self.test_emp_covs, _ = empirical_covariances(test_subjs)
      self.verbose = verbose
  
imports: import collections.abc
  import itertools
  import operator
  import warnings
  import numpy
  import scipy.linalg
  from joblib import Memory, Parallel, delayed
  from sklearn.base import BaseEstimator
  from sklearn.covariance import empirical_covariance
  from sklearn.model_selection import check_cv
  from sklearn.utils.extmath import fast_logdet
  from .._utils import CacheMixin, logger
  from .._utils.extmath import is_spd
label_desc: Use image node_id 1 to create a new EarlyStopProbe object  with example: obj = EarlyStopProbe(test_subjs, verbose)