void (@Nullable GrExpression lhs) { if (!(lhs instanceof GrReferenceExpression)) { return; } final PsiElement referent = ((PsiReference) lhs).resolve(); if (referent == null) { return; } if (!(referent instanceof GrParameter)) { return; } if (referent.getParent() instanceof GrForClause) { return; } registerError(lhs); }