@Nullable
  @Override
  public GrTupleAssignmentExpression getParent() {
    PsiElement parent = super.getParent();
    assert parent == null || parent instanceof GrTupleAssignmentExpression : parent.getClass().getName();
    return (GrTupleAssignmentExpression)parent;
  }
@Nullable
  @Override
  public GrTupleAssignmentExpression getParent()