code: def test_dimensional_expr_of_derivative():
      l = Quantity("l")
      t = Quantity("t")
      t1 = Quantity("t1")
      l.set_global_relative_scale_factor(36, km)
      t.set_global_relative_scale_factor(1, hour)
      t1.set_global_relative_scale_factor(1, second)
      x = Symbol("x")
      y = Symbol("y")
      f = Function("f")
      dfdx = f(x, y).diff(x, y)
      dl_dt = dfdx.subs({f(x, y): l, x: t, y: t1})
      assert (
          SI.get_dimensional_expr(dl_dt)
          == SI.get_dimensional_expr(l / t / t1)
          == Symbol("length") / Symbol("time") ** 2
      )
      assert (
          SI._collect_factor_and_dimension(dl_dt)
          == SI._collect_factor_and_dimension(l / t / t1)
          == (10, length / time**2)
      )
  
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 20 for calling a global function with example usage: test_dimensional_expr_of_derivative() without return types