Factorise :$\displaystyle 2a^4+a^2b^2+ab^3+b^4$

I could not solve this problem for factorisation. I tried a various things like grouping terms from which common factor can be taken out. Then ,as it is a degree 4 polynomial, I tried adjust terms so that the polynomial can be written as product of 4 binomials and many other things. but nothing worked out. Complex factors are not allowed. Please help me.