'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)
    x = arg_objs[0]
    ones = lu.create_const(np.mat(np.ones(size)), size)
    return (t, [ExpCone(t, x, ones)])
