equivalent of "quad_form" when using Optistack( ) symbolic expresssions

[Jushan-Randy-Chen]

It seems like the quad_form function does not exist when using Optistack( ) symbolic operations. I have a vector x as a Opti variable, and a constant numerical matrix Q, but when I do quad_form(x,Q) the following error is returned:

AttributeError: module 'casadi' has no attribute 'quad_form'

Is there an equivalent function to use? Otherwise it would be super inconvenient to do a double for loop to sum up all the element-wise multiplications