fixed error in doctest
fixed error in doctest

sgiavasis/nipype,sgiavasis/nipype,FCP-INDI/nipype,FCP-INDI/nipype,dgellis90/nipype,pearsonlab/nipype,FCP-INDI/nipype,pearsonlab/nipype,iglpdc/nipype,mick-d/nipype,sgiavasis/nipype,mick-d/nipype,FCP-INDI/nipype,dgellis90/nipype,carolFrohlich/nipype,iglpdc/nipype,dgellis90/nipype,pearsonlab/nipype,pearsonlab/nipype,mick-d/nipype,dgellis90/nipype,carolFrohlich/nipype,carolFrohlich/nipype,sgiavasis/nipype,mick-d/nipype,iglpdc/nipype,iglpdc/nipype,carolFrohlich/nipype