fix(injector): don't visit FunctionDeclarations more than once
fix(injector): don't visit FunctionDeclarations more than once

oliviertassinari/material-ui,rscnt/material-ui,rscnt/material-ui,mbrookes/material-ui,callemall/material-ui,rscnt/material-ui,oliviertassinari/material-ui,callemall/material-ui,mbrookes/material-ui,mui-org/material-ui,mui-org/material-ui,callemall/material-ui,mbrookes/material-ui,mui-org/material-ui,callemall/material-ui,oliviertassinari/material-ui