added example for Map query
added example for Map query

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