# History, Design and Future { #history-design-and-future }

Some time ago, [a **FastAPI** user asked](https://github.com/fastapi/fastapi/issues/3#issuecomment-454956920):

> What’s the history of this project? It seems to have come from nowhere to awesome in a few weeks [...]

Here's a little bit of that history.

## Alternatives { #alternatives }

  }

  @Test
  fun defaultExpirationDateConditionallyCached() {
    //      last modified: 115 seconds ago
    //             served:  15 seconds ago
    //   default lifetime: (115 - 15) / 10 = 10 seconds
    //            expires:  10 seconds from served date = 5 seconds ago
    val lastModifiedDate = formatDate(-115, TimeUnit.SECONDS)
    val conditionalRequest =
      assertConditionallyCached(

 * of the code may not be readable by older versions of the code (e.g., a serialized Bloom filter
 * generated today may <i>not</i> be readable by a binary that was compiled 6 months ago).
 *
 * <p>As of Guava 23.0, this class is thread-safe and lock-free. It internally uses atomics and
 * compare-and-swap to ensure correctness when multiple threads are used to access it.
 *

Python 3.6 reached the [end-of-life and is no longer supported by Python](https://www.python.org/downloads/release/python-3615/) since around a year ago.

You hopefully updated to a supported version of Python a while ago. If you haven't, you really should.

### Features