Added a test case for split_super_sub() function
Added a test case for split_super_sub() function

yashsharan/sympy,skidzo/sympy,skidzo/sympy,skidzo/sympy,yashsharan/sympy,kaushik94/sympy,madan96/sympy,madan96/sympy,yashsharan/sympy,chaffra/sympy,madan96/sympy,chaffra/sympy,chaffra/sympy,jaimahajan1997/sympy,kaushik94/sympy,kaushik94/sympy,jaimahajan1997/sympy,jaimahajan1997/sympy