Add tests for get_parents function
Add tests for get_parents function

yashu-seth/pgmpy,jhonatanoliveira/pgmpy,ankurankan/pgmpy,pgmpy/pgmpy,vivek425ster/pgmpy,pratyakshs/pgmpy,yashu-seth/pgmpy,liquidmetal/pgmpy,kislayabhi/pgmpy,jhonatanoliveira/pgmpy,ankurankan/pgmpy,vivek425ster/pgmpy,liquidmetal/pgmpy,kris-singh/pgmpy,anaviltripathi/pgmpy,abinashpanda/pgmpy,abinashpanda/pgmpy,khalibartan/pgmpy,khalibartan/pgmpy,sandeepkrjha/pgmpy,pgmpy/pgmpy,pratyakshs/pgmpy,kris-singh/pgmpy,anaviltripathi/pgmpy,palashahuja/pgmpy,sandeepkrjha/pgmpy,kislayabhi/pgmpy,palashahuja/pgmpy