class_docstr: A CustomCallback can be created by override its parent `Callback` class
  and by implementing the desired logic in its available methods.
docstr: Initialization method for the customized callback.
code: def __init__(self):
      """Initialization method for the customized callback."""
  
      # You only need to override its parent class
      super(CustomCallback).__init__()
  
file_path: opytimizer/examples/utils/custom_callbacks.py
imports: from opytimizer.utils.callback import Callback
label_desc: Use image node_id 1 to create a new CustomCallback object from inherited base classes: Callback with example: obj = CustomCallback()