class_docstr: Generates a dot description of a ssa block
code: def labeller(self, labeller):
      self.alternate_labeller = labeller
      return self
  
file_path: coremltools/coremltools/converters/mil/mil/visitors/dot_visitor.py
imports: from ..var import Var
label_desc: Use image node_id 2 for calling the DotVisitor obj's underlying member method code with example usage: obj.labeller(labeller) and returns: self