class_docstr: Leave-One-Label_Out cross-validation iterator:
  Provides train/test indexes to split data in train test sets
code: def __repr__(self):
      return "{}.{}(labels={})".format(
          self.__class__.__module__,
          self.__class__.__name__,
          self.labels,
      )
  
imports: from statsmodels.compat.python import lrange
  import numpy
  from itertools import combinations
label_desc: Use image node_id 3 for calling the LeaveOneLabelOut obj's underlying member method code with example usage: obj.__repr__() and returns: str