Assertion using groovy sometimes throws java.lang,NullPointerException

Hi,

when i try to assert a group assertion like:

assert slurperresponse.values.data.name.person== true
assert slurperresponse.values.data.address.person== true
assert slurperresponse.values.data.car.person== true
assert slurperresponse.values.data.city.person== true
assert slurperresponse.values.data.country.person== true
assert slurperresponse.values.data.province.person== true
assert slurperresponse.values.data.code.person== true
assert slurperresponse.values.data.group.person== true

It works for sometime.

After sometime it throws java.lang.NullPointerException saying java.lang.NullPointerException:Cannot get person on null object.

If i remove the last assertion it works again.

i tried this:

if(slurperresponse.values.data.group.person != null){

assert slurperresponse.values.data.group.person== true

}

i got the same error.

If i wait for sometime then it works.

Is there a probleme with memory leak or garbage collection .

Did someone notice this behavior ?

Or is there a better way to reduce all lines?

Thank you