class_docstr: Generate code for a fused-type special function that can be
  cimported in Cython.
code: def _get_vars(self):
      invars = [f"x{n}" for n in range(len(self.intypes))]
      outvars = [f"y{n}" for n in range(len(self.outtypes))]
      return invars, outvars
  
imports: import itertools
  import json
  import os
  from stat import ST_MTIME
  import argparse
  import re
  import textwrap
  import numpy
label_desc: Use image node_id 4 for calling the FusedFunc obj's underlying member method code with example usage: obj._get_vars() and returns: invars,  outvars