code: def test_physics_constant():
      from sympy.physics.units import definitions
  
      for name in dir(definitions):
          quantity = getattr(definitions, name)
          if not isinstance(quantity, Quantity):
              continue
          if name.endswith("_constant"):
              assert isinstance(
                  quantity, PhysicalConstant
              ), f"{quantity} must be PhysicalConstant, but is {type(quantity)}"
              assert (
                  quantity.is_physical_constant
              ), f"{name} is not marked as physics constant when it should be"
  
      for const in [
          gravitational_constant,
          molar_gas_constant,
          vacuum_permittivity,
          speed_of_light,
          elementary_charge,
      ]:
          assert isinstance(
              const, PhysicalConstant
          ), f"{const} must be PhysicalConstant, but is {type(const)}"
          assert (
              const.is_physical_constant
          ), f"{const} is not marked as physics constant when it should be"
  
      assert not meter.is_physical_constant
      assert not joule.is_physical_constant
  
imports: import warnings
  from sympy.core.add import Add
  from sympy.core.function import Function, diff
  from sympy.core.numbers import Number, Rational
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.functions.elementary.complexes import Abs
  from sympy.functions.elementary.exponential import exp, log
  from sympy.functions.elementary.miscellaneous import sqrt
  from sympy.functions.elementary.trigonometric import sin
  from sympy.integrals.integrals import integrate
  from sympy.physics.units import amount_of_substance, area, convert_to, find_unit, volume, kilometer, joule, molar_gas_constant, vacuum_permittivity, elementary_charge, volt, ohm
  from sympy.physics.units.definitions import amu, au, centimeter, coulomb, day, foot, grams, hour, inch, kg, km, m, meter, millimeter, minute, quart, s, second, speed_of_light, bit, byte, kibibyte, mebibyte, gibibyte, tebibyte, pebibyte, exbibyte, kilogram, gravitational_constant, electron_rest_mass
  from sympy.physics.units.definitions.dimension_definitions import Dimension, charge, length, time, temperature, pressure, energy, mass
  from sympy.physics.units.prefixes import PREFIXES, kilo
  from sympy.physics.units.quantities import PhysicalConstant, Quantity
  from sympy.physics.units.systems import SI
  from sympy.testing.pytest import raises
label_desc: Use image node_id 33 for calling a global function with example usage: test_physics_constant() without return types