class_docstr: A template estimator to be used as a reference implementation.
  
  For more information regarding how to build your own estimator, read more
  in the :ref:`User Guide <user_guide>`.
  
  Parameters
  ----------
  demo_param : str, default='demo_param'
      A parameter used for demonstation of how to pass and store paramters.
code: def __init__(self, demo_param="demo_param"):
      self.demo_param = demo_param
  
imports: from sklearn.base import BaseEstimator, ClassifierMixin, TransformerMixin
  from sklearn.metrics import euclidean_distances
  from sklearn.utils.multiclass import unique_labels
  from sklearn.utils.validation import check_array, check_is_fitted, check_X_y
  import geomstats.backend
label_desc: Use image node_id 1 to create a new TemplateEstimator object from inherited base classes: BaseEstimator with example: obj = TemplateEstimator(demo_param)