class_docstr: Sanitize the names of vars and ops to make sure
  that they are of the format as described in the NameSanitizer class, i.e.
  of the format [a-zA-Z_][a-zA-Z0-9_]*
class_docstr_tok: ["Sanitize","the","names","of","vars","and","ops","to","make","sure","that","they","are","of","the","format","as","described","in","the","NameSanitizer","class",",","i.e",".","of","the","format","[","a-zA-Z_","]","[","a-zA-Z0-9_","]","*"]
code: def apply(self, prog):
      for f in prog.functions.values():
          sanitizer_vars = NameSanitizer(prefix="var_")
          sanitizer_ops = NameSanitizer(prefix="op_")
          NameSanitizer.sanitize_block(
              f, sanitizer_vars, sanitizer_ops, prog.main_input_types
          )
  
imports: from coremltools.converters.mil.mil.passes.defs.preprocess import NameSanitizer
  from coremltools.converters.mil.mil.passes.graph_pass import AbstractGraphPass
  from coremltools.converters.mil.mil.passes.pass_registry import register_pass
label_desc: Use image node_id 1 for calling the sanitize_name_strings obj's underlying member method code with example usage: obj.apply(prog) without return types