code: def tol():
      """Numerical tolerance for equality tests."""
      return float(os.environ.get("TOL", TOL))
  
imports: import os
  import pathlib
  import numpy
  import pytest
  import pennylane
  from pennylane.devices import DefaultGaussian
label_desc: Use image node_id 1 for calling a global function with example usage: tol() and returns: float