fix writer class
fix writer class

yashu-seth/pgmpy,palashahuja/pgmpy,sandeepkrjha/pgmpy,jhonatanoliveira/pgmpy,liquidmetal/pgmpy,kris-singh/pgmpy,ankurankan/pgmpy,ankurankan/pgmpy,palashahuja/pgmpy,yashu-seth/pgmpy,anaviltripathi/pgmpy,liquidmetal/pgmpy,abinashpanda/pgmpy,abinashpanda/pgmpy,anaviltripathi/pgmpy,kris-singh/pgmpy,sandeepkrjha/pgmpy,pratyakshs/pgmpy,khalibartan/pgmpy,pgmpy/pgmpy,pgmpy/pgmpy,pratyakshs/pgmpy,jhonatanoliveira/pgmpy,khalibartan/pgmpy