class_docstr: Represents unevaluated oriented additions.
  Parent class for Integral and Sum.
code: def _eval_factor(self, **hints):
      if 1 == len(self.limits):
          summand = self.function.factor(**hints)
          if summand.is_Mul:
              out = sift(
                  summand.args,
                  lambda w: w.is_commutative
                  and not set(self.variables) & w.free_symbols,
              )
              return Mul(*out[True]) * self.func(
                  Mul(*out[False]), *self.limits
              )
      else:
          summand = self.func(
              self.function, *self.limits[0:-1]
          ).factor()
          if not summand.has(self.variables[-1]):
              return self.func(1, [self.limits[-1]]).doit() * summand
          elif isinstance(summand, Mul):
              return self.func(summand, self.limits[-1]).factor()
      return self
  
imports: from sympy.core.add import Add
  from sympy.core.containers import Tuple
  from sympy.core.expr import Expr
  from sympy.core.function import AppliedUndef, UndefinedFunction
  from sympy.core.mul import Mul
  from sympy.core.relational import Equality, Relational
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, Dummy
  from sympy.core.sympify import sympify
  from sympy.functions.elementary.piecewise import piecewise_fold, Piecewise
  from sympy.logic.boolalg import BooleanFunction
  from sympy.matrices.matrixbase import MatrixBase
  from sympy.sets.sets import Interval, Set
  from sympy.sets.fancysets import Range
  from sympy.tensor.indexed import Idx
  from sympy.utilities import flatten
  from sympy.utilities.iterables import sift, is_sequence
  from sympy.utilities.exceptions import sympy_deprecation_warning
label_desc: Use image node_id 5 for calling the AddWithLimits obj's underlying member method code with example usage: obj._eval_factor() and returns: self, unknown, unknown, self