Details about the `async def` syntax for *path operation functions* and some background about asynchronous code, concurrency, and parallelism.

## In a hurry? { #in-a-hurry }

<abbr title="too long; didn't read"><strong>TL;DR:</strong></abbr>

If you are using third party libraries that tell you to call them with `await`, like:

```Python
results = await some_library()
```

            // Use the recommended version from the specified VersionRange since there is no
            // original recommended version
            version = restriction.recommendedVersion;
        }
        /* TODO should throw this immediately, but need artifact
                else
                {
                    throw new OverConstrainedVersionException( "Restricting incompatible version ranges" );
                }

        }
        if (StringUtil.isNotBlank(boostDocumentRulePager.boostExpr)) {
            cb.query().setBoostExpr_Wildcard(wrapQuery(boostDocumentRulePager.boostExpr));
        }
        // TODO Long, Integer, String supported only.

        // setup condition
        cb.query().addOrderBy_SortOrder_Asc();
        cb.query().addOrderBy_CreatedTime_Asc();

        // search

    }

        }
        if (StringUtil.isNotBlank(pathMappingPager.replacement)) {
            cb.query().setReplacement_Wildcard(wrapQuery(pathMappingPager.replacement));
        }
        // TODO Long, Integer, String supported only.

        // setup condition
        cb.query().addOrderBy_SortOrder_Asc();
        cb.query().addOrderBy_CreatedTime_Asc();

        // search

    }

    }

    /**
     * Returns the current time in milliseconds.
     *
     * @return the current time in milliseconds
     */
    public static long currentTimeMillis() {
        // TODO provider
        return System.currentTimeMillis();
    }

               * case we ever switch to JUnit 4:
               */
              fail();
            }
          }
        });
  }

  // TODO(cpovirk): promote to Uninterruptibles, and add untimed version
  private static void joinUninterruptibly(Thread thread, long timeout, TimeUnit unit) {
    boolean interrupted = false;
    try {

   *     such index exists.
   */
  public static int indexOf(boolean[] array, boolean target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public
  private static int indexOf(boolean[] array, boolean target, int start, int end) {
    for (int i = start; i < end; i++) {
      if (array[i] == target) {
        return i;
      }

   *     such index exists.
   */
  public static int indexOf(boolean[] array, boolean target) {
    return indexOf(array, target, 0, array.length);
  }

  // TODO(kevinb): consider making this public
  private static int indexOf(boolean[] array, boolean target, int start, int end) {
    for (int i = start; i < end; i++) {
      if (array[i] == target) {
        return i;
      }

          // if this is a concern we could add special cases for some known charsets (like utf8)
          // or we could avoid inputstreamreader and use the decoder api directly
          // TODO(lukes): in a real implementation we would need to handle overflow conditions
          int maxChars = (int) (size.get().intValue() * cs.newDecoder().maxCharsPerByte());
          char[] buffer = new char[maxChars];

    assertTrue(concurrentlyMutatedList.getAllStates().contains(copyOfIterable));
  }

  private static void runConcurrentlyMutatedTest(WrapWithIterable wrap) {
    /*
     * TODO: Iterate over many array sizes and all possible operation lists,
     * performing adds and removes in different ways.
     */
    runConcurrentlyMutatedTest(elements(), ops(add(1), add(2)), wrap);