Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Date | Visitor | Score | Home | Decision | Attendance | Series |
| --- | --- | --- | --- | --- | --- | --- |
| May 15 | Buffalo | 1 – 4 | Philadelphia | Parent | 17077.0 | Flyers lead 1–0 |
| May 18 | Buffalo | 1 – 2 | Philadelphia | Parent | 17077.0 | Flyers lead 2–0 |
| May 20 | Philadelphia | 4 – 5 | Buffalo | Parent | 15863.0 | Flyers lead 2–1 |
| May 22 | Philadelphia | 2 – 4 | Buffalo | Parent | 15863.0 | Series tied 2–2 |
| May 25 | Buffalo | 1 – 5 | Philadelphia | Parent | 17077.0 | Flyers lead 3–2 |
| May 27 | Philadelphia | 2 – 0 | Buffalo | Parent | 15863.0 | Flyers win 4–2 |
Question:
who is the Visitor that has a Series of series tied 2–2?
Answer:
Philadelphia