Added check for headers set to None
Added check for headers set to None

crchemist/scioncc,scionrep/scioncc,mkl-/scioncc,crchemist/scioncc,scionrep/scioncc,mkl-/scioncc,scionrep/scioncc,ooici/pyon,mkl-/scioncc,ooici/pyon,crchemist/scioncc