**FastAPI** is fully compatible with (and based on) <a href="https://www.starlette.io/" class="external-link" target="_blank"><strong>Starlette</strong></a>. So, any additional Starlette code you have, will also work.

`FastAPI` is actually a sub-class of `Starlette`. So, if you already know or use Starlette, most of the functionality will work the same way.

With **FastAPI** you get all of **Starlette**'s features (as FastAPI is just Starlette on steroids):

  }

  private static final class UnknownElementException extends RuntimeException {
    private UnknownElementException(Collection<?> expected, Object actual) {
      super("Returned value '" + actual + "' not found. Remaining elements: " + expected);
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**

            return null;
        });

    }

    // -----------------------------------------------------
    //                                         Actually Crud
    //                                         -------------
    /**
     * Create a stemmer override item.
     * @param form The create form.
     * @return The HTML response.
     */
    @Execute

    extends AbstractMap<K, V> implements Serializable {
  /*
   * TODO: Make this a drop-in replacement for j.u. versions, actually drop them in, and test the
   * world. Figure out what sort of space-time tradeoff we're actually going to get here with the
   * *Map variants. This class is particularly hard to benchmark, because the benefit is not only in

 * - canonical URL path: path component of the URL: this is used to reconstruct URLs to resources and is not adjusted by
 * DFS referrals. (E.g. a resource with a DFS root's parent will still point to the DFS root not the share it's actually
 * located in).
 * - share + uncpath within it: This is the relevant information for most SMB requests. Both are adjusted by DFS
 * referrals. Nested resources will inherit the information already resolved by the parent resource.

        connect0();
        dest.connect0();

        /* At this point the maxBufferSize values are from the server
         * exporting the volumes, not the one that we will actually
         * end up performing IO with. If the server hosting the
         * actual files has a smaller maxBufSize this could be
         * incorrect. To handle this properly it is necessary
         * to redirect the tree to the target server first before

  }

  private static final class UnknownElementException extends RuntimeException {
    private UnknownElementException(Collection<?> expected, Object actual) {
      super("Returned value '" + actual + "' not found. Remaining elements: " + expected);
    }

    @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;
  }

  /**

        assertNotNull(result);
        assertTrue(result.contains("Session Id:"));
        assertNotNull(pythonJob.sessionId);
        assertTrue(pythonJob.sessionId.length() >= 10);

        // The test doesn't actually call the real process since ServletContext.getRealPath returns null in test
        // and causes an exception which is caught and added to result
        assertTrue(result.contains("Session Id:"));
    }

   * {@link Builder} and call {@link Builder#orderRowsBy}, {@link Builder#orderColumnsBy}, and
   * {@link Builder#putAll}
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   */

   *
   * <p>The returned {@code BiMap} iterates over entries in the same order as the {@code entrySet}
   * of the original map.
   *
   * <p>Despite the method name, this method attempts to avoid actually copying the data when it is
   * safe to do so. The exact circumstances under which a copy will or will not be performed are
   * undocumented and subject to change.
   *