human
Solve the following python programming problem given the following code:
def factor_nc(expr) : 
    "Return the factored form of ``expr`` while handling non-commutative
    expressions.

    Examples
    ========

    >>> from sympy.core.exprtools import factor_nc
    >>> from sympy import Symbol
    >>> from sympy.abc import x
    >>> A = Symbol('A', commutative=False)
    >>> B = Symbol('B', commutative=False)
    >>> factor_nc((x**2 + 2*A*x + A**2).expand())
    (x + A)**2
    >>> factor_nc(((x + A)*(x + B)).expand())
    (x + A)*(x + B)
    " 
    from sympy.simplify.simplify import powsimp 
    from sympy.polys import gcd, factor 
    def _pemexpand(expr) : 
        'Expand with the minimal set of hints necessary to check the result.' 
        return expr.expand (deep = True, mul = True, power_exp = True, power_base = False, basic = False, multinomial = True, log = False) 
expr = sympify (expr) 
    if ((not isinstance (expr, Expr)) or (not expr.args)) : 
        return expr 
if (not expr.is_Add) : 
        return expr.func (* [factor_nc (a) for a in expr.args]) 
(expr, rep, nc_symbols) = _mask_nc (expr) 
    if rep : 
        return factor (expr).subs (rep) 
else : 
        args = [a.args_cnc () for a in Add.make_args (expr)] 
        c = g = l = r = S.One 
        hit = False 
        for (i, a) in enumerate (args) : 
            if (i == 0) : 
                c = Mul._from_args (a [0]) 
else : 
                if a [0] : 
                    c = gcd (c, Mul._from_args (a [0])) 
else : 
                    c = S.One 
if (c is not S.One) : 
            hit = True 
            (c, g) = c.as_coeff_Mul () 
            if (g is not S.One) : 
                for (i, (cc, _)) in enumerate (args) : 
                    cc = list (Mul.make_args ((Mul._from_args (list (cc)) / g))) 
                    args [i] [0] = cc 
for (i, (cc, _)) in enumerate (args) : 
                cc [0] = (cc [0] / c) 
                args [i] [0] = cc 
for (i, a) in enumerate (args) : 
            if (i == 0) : 
                n = a [1] [:] 
else : 
                n = common_prefix (n, a [1]) 
if (not...

    
    

    Fix the buggy line: return _keep_coeff (c, (((g * l) * _pemexpand) * r))
assistant
#Here is Python program to fix the buggy line: return _keep_coeff (c, (((g * l) * _pemexpand) * r))
.

return _keep_coeff (c, (((g * l) * new_mid) * r))