code: def _iszero(x):
      """Returns True if x is zero."""
      return getattr(x, "is_zero", None)
  
file_path: sympy/sympy/matrices/utilities.py
imports: from contextlib import contextmanager
  from threading import local
  from sympy.core.function import expand_mul
label_desc: Use image node_id 5 for calling a global function with example usage: _iszero(x) and returns: getattr