human
Solve the following python programming problem given the following code:
def check_invalid_numexpr_version(engine, parser) : 
    def testit() : 
        (a, b) = (1, 2) 
        res = pd.eval ('a + b', engine = engine, parser = parser) 
        tm.assert_equal (res, 3) 
if (testit == 'numexpr') : 
        try : 
            import numexpr as ne 
except ImportError : 
            raise nose.SkipTest ('no numexpr') 
else : 
            if (ne.__version__ < LooseVersion ('2.1')) : 
                with tm.assertRaisesRegexp (ImportError, "'numexpr' version is .+, must be >= 2.1") : 
                    testit () 
else : 
                if (ne.__version__ == LooseVersion ('2.4.4')) : 
                    raise nose.SkipTest ('numexpr version==2.4.4') 
else : 
                    testit () 
else : 
        testit () 

    
    

    Fix the buggy line: if (testit == 'numexpr') :
assistant
#Here is Python program to fix the buggy line: if (testit == 'numexpr') :
.

if (engine == 'numexpr') :