/**
 * @name Test for usings
 */
import csharp

from Method m, LocalVariable v
where m.hasName("MainUsing")
  and v.getVariableDeclExpr().getEnclosingCallable() = m
  and v.getVariableDeclExpr().getParent() instanceof UsingStmt
  and v.hasName("w")
  and v.getType().hasName("TextWriter")
select m, v
