* and column pair, they will be combined with the specified merging function in encounter order.
   *
   * <p>The returned {@code Collector} will throw a {@code NullPointerException} at collection time
   * if the row, column, value, or merging functions return null on any input.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */

   *
   * <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}), the
   * values are merged using the specified merging function. If the merging function returns {@code
   * null}, then the collector removes the value that has been computed for the key thus far (though
   * future occurrences of the key would reinsert it).
   *

   *
   * <p>If the mapped keys contain duplicates (according to {@link Object#equals(Object)}), the
   * values are merged using the specified merging function. If the merging function returns {@code
   * null}, then the collector removes the value that has been computed for the key thus far (though
   * future occurrences of the key would reinsert it).
   *

   * elements.
   *
   * <p>If the mapped keys contain duplicates (according to the comparator), the values are merged
   * using the specified merging function. Entries will appear in the encounter order of the first
   * occurrence of the key.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */
  @SuppressWarnings("Java7ApiChecker")

   * elements.
   *
   * <p>If the mapped keys contain duplicates (according to the comparator), the values are merged
   * using the specified merging function. Entries will appear in the encounter order of the first
   * occurrence of the key.
   *
   * @since 21.0
   */
  public static <T extends @Nullable Object, K, V>

* Add external link [Machine learning model serving in Python using FastAPI and Streamlit](https://davidefiocco.github.io/2020/06/27/streamlit-fastapi-ml-serving.html) to docs. PR [#1669](https://github.com/tiangolo/fastapi/pull/1669) by [@davidefiocco](https://github.com/davidefiocco).

Run the server with:

<div class="termy">

```console
$ fastapi dev main.py

 ╭────────── FastAPI CLI - Development mode ───────────╮
 │                                                     │
 │  Serving at: http://127.0.0.1:8000                  │
 │                                                     │
 │  API docs: http://127.0.0.1:8000/docs               │
 │                                                     │