GraphSubstituteExpr  173 src/Substitute.cpp     GraphSubstituteExpr(const Expr &find, const Expr &replace) : find(find), replace(replace) {}
GraphSubstituteExpr  185 src/Substitute.cpp     return GraphSubstituteExpr(find, replacement).mutate(expr);
GraphSubstituteExpr  189 src/Substitute.cpp     return GraphSubstituteExpr(find, replacement).mutate(stmt);