class_docstr: Prune to an exact pruning level specification
  
  Attributes
  ----------
  mask_dict : dict
      Dictionary for saving masks, `key` should be layer name and
      `value` should be a tensor which has the same shape with layer's weight
code: def compress(self):
      self.update_mask()
      return self.bound_model
  
imports: import types
  import logging
  import torch
  from .None import default_layers
label_desc: Use image node_id 2 for calling the Pruner obj's underlying member method code with example usage: obj.compress() and returns: self