code: def _is_variable_int(x):
      return type(x) is not int
  
file_path: funsor/funsor/ops/tracer.py
imports: from collections import OrderedDict
  from functools import singledispatch
  from .array import is_numeric_array
  from .op import trace_ops
  from .program import OpProgram
label_desc: Use image node_id 4 for calling a global function with example usage: _is_variable_int(x) and returns: unknown