Made UGen instantiation more strict.
Made UGen instantiation more strict.

Pulgama/supriya,josiah-wolf-oberholtzer/supriya,andrewyoung1991/supriya,andrewyoung1991/supriya,Pulgama/supriya,Pulgama/supriya,Pulgama/supriya,andrewyoung1991/supriya