code: def to_list(self, to_dict=False):
      if self.is_singleton():
          spec = self.singleton()
          if isinstance(spec, self.value_type):
              return spec
          else:
              return spec.to_list()
  
      else:
          return [
              spec
              if isinstance(spec, self.value_type)
              else (spec.to_dict() if to_dict else spec.to_list())
              for spec in super(NestedDict, self).values()
              if isinstance(spec, self.value_type) or len(spec) > 0
          ]
  
imports: from collections import OrderedDict
  import numpy
  import tensorflow
  from tensorflow.python.training.tracking.tracking import AutoTrackable
  from tensorflow.python.training.tracking.data_structures import sticky_attribute_assignment
  from tensorforce.core.utils import NestedDict
label_desc: Use image node_id 4 for calling the SignatureDict obj's underlying member method code with example usage: obj.to_list(to_dict) and returns: unknown, spec, spec