code: def tail(self):
      # If required, draw leaf nodes at same depth as each other
      if self.leaves_parallel:
          for rank in sorted(self.ranks):
              self.out_file.write(
                  "{rank=same ; "
                  + "; ".join(r for r in self.ranks[rank])
                  + "} ;\n"
              )
      self.out_file.write("}")
  
imports: from collections.abc import Iterable
  from io import StringIO
  from numbers import Integral
  import numpy
  from ..base import is_classifier
  from ..utils._param_validation import HasMethods, Interval, StrOptions, validate_params
  from ..utils.validation import check_array, check_is_fitted
  from .None import DecisionTreeClassifier, DecisionTreeRegressor, _criterion, _tree
  from ._reingold_tilford import Tree, buchheim
label_desc: Use image node_id 3 for calling the _DOTTreeExporter obj's underlying member method code with example usage: obj.tail() without return types