code: def __init__(self, call_deps=False):
      self.graph = DiGraph()
      self.modified = set()
      self.used = set()
      self.undefined = set()
      self.sources = set()
      self.targets = set()
  
      self.context_names = set()
  
      self.call_deps = call_deps
  
imports: from __future__ import print_function
  from __future__ import division
  from __future__ import absolute_import
  from ...asttools import Visitor, visit_children
  import _ast
  from ...asttools.visitors.symbol_visitor import get_symbols
label_desc: Use image node_id 1 to create a new CollectNodes object from inherited base classes: Visitor with example: obj = CollectNodes(call_deps)