'Reduces the atom to an affine expression and list of constraints.
Parameters
arg_objs : list
LinExpr for each argument.
size : tuple
The size of the resulting expression.
data :
Additional data required by the atom.
Returns
tuple
(LinOp for objective, list of constraints)'

@staticmethod
def graph_implementation(arg_objs, size, data=None):

    t = lu.create_var(size)
    constraints = []
    for obj in arg_objs:
        obj = Elementwise._promote(obj, size)
        constraints.append(lu.create_leq(obj, t))
    return (t, constraints)
