Added the docstring.
Added the docstring.

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