[NTG-context] graphics "styles"

Hi! In tikz I can say \draw[help lines] (0, 0) circle (1cm); and setup what does "help lines" mean (color, linewidth etc.) in the environment file with \tikzset{help lines/.style={...}}. Is there any way to do something similar with ConTeXt+MetaPost? Should I add drawoptions(\MPvar{another-style-name}) before each draw/fill command, and drawoptions() after it?