code: def _get_constant_subexpressions(expr, Cs):
      Cs = set(Cs)
      Ces = []
  
      def _recursive_walk(expr):
          expr_syms = expr.free_symbols
          if expr_syms and expr_syms.issubset(Cs):
              Ces.append(expr)
          else:
              if expr.func == exp:
                  expr = expr.expand(mul=True)
              if expr.func in (Add, Mul):
                  d = sift(
                      expr.args, lambda i: i.free_symbols.issubset(Cs)
                  )
                  if len(d[True]) > 1:
                      x = expr.func(*d[True])
                      if not x.is_number:
                          Ces.append(x)
              elif isinstance(expr, Integral):
                  if expr.free_symbols.issubset(Cs) and all(
                      len(x) == 3 for x in expr.limits
                  ):
                      Ces.append(expr)
              for i in expr.args:
                  _recursive_walk(i)
          return
  
      _recursive_walk(expr)
      return Ces
  
imports: from sympy.core import Add, S, Mul, Pow, oo
  from sympy.core.containers import Tuple
  from sympy.core.expr import AtomicExpr, Expr
  from sympy.core.function import Function, Derivative, AppliedUndef, diff, expand, expand_mul, Subs
  from sympy.core.multidimensional import vectorize
  from sympy.core.numbers import nan, zoo, Number
  from sympy.core.relational import Equality, Eq
  from sympy.core.sorting import default_sort_key, ordered
  from sympy.core.symbol import Symbol, Wild, Dummy, symbols
  from sympy.core.sympify import sympify
  from sympy.core.traversal import preorder_traversal
  from sympy.logic.boolalg import BooleanAtom, BooleanTrue, BooleanFalse
  from sympy.functions import exp, log, sqrt
  from sympy.functions.combinatorial.factorials import factorial
  from sympy.integrals.integrals import Integral
  from sympy.polys import Poly, terms_gcd, PolynomialError, lcm
  from sympy.polys.polytools import cancel
  from sympy.series import Order
  from sympy.series.series import series
  from sympy.simplify import collect, logcombine, powsimp, separatevars, simplify, cse
  from sympy.simplify.radsimp import collect_const
  from sympy.solvers import checksol, solve
  from sympy.utilities import numbered_symbols
  from sympy.utilities.iterables import uniq, sift, iterable
  from sympy.solvers.deutils import _preprocess, ode_order, _desolve
  from .single import SingleODEProblem, SingleODESolver, solver_map
label_desc: Use image node_id 16 for calling a global function with example usage: _get_constant_subexpressions(expr, Cs) and returns: Ces