[NTG-context] apply typing environment to \typebuffer

Dear list, I have a presentation that defines a typing environment and I would like to know who to apply it to \typebuffer. Here is a sample: \definetyping[TeXcode][option=TEX] \starttext \startbuffer[a] \starttext \input knuth \stoptext \stopbuffer \typesetbuffer[a] \typebuffer[a] \stoptext Of course, the defined typing environment is richer in the presentation. How could I get \typebuffer to use TeXcode? Many thanks for your help, Pablo -- http://www.ousia.tk