class_docstr: Base class for instanes that stack job estimators
docstr: Push onto stack
docstr_tok: ["Push","onto","stack"]
code: def push(self, *stack):
      """Push onto stack"""
      check_stack(stack, self.stack)
      for item in stack:
          self.stack.append(item)
          attr = item.name.replace("-", "_").replace(" ", "").strip()
          setattr(self, attr, item)
      return self
  
imports: import warnings
  from abc import abstractmethod
  import numpy
  from ._base_functions import check_stack, check_params
  from ..None import config
  from ..utils.exceptions import ParallelProcessingError
  from ..externals.sklearn.base import clone, BaseEstimator
label_desc: Use image node_id 3 for calling the BaseStacker obj's underlying member method code with example usage: obj.push() and returns: self