class_docstr: Base class for all estimators in scikit-learn
  Notes
  -----
  All estimators should specify all the parameters that can be set
  at the class level in their ``__init__`` as explicit keyword
  arguments (no ``*args`` or ``**kwargs``).
code: def __repr__(self):
      class_name = self.__class__.__name__
      return "%s(%s)" % (
          class_name,
          _pprint(
              self.get_params(deep=False),
              offset=len(class_name),
          ),
      )
  
imports: import copy
  import warnings
  from collections import defaultdict
  import numpy
  from scipy import sparse
  from ..None import six
  from ..funcsigs import signature
label_desc: Use image node_id 4 for calling the BaseEstimator obj's underlying member method code with example usage: obj.__repr__() and returns: unknown