# Simple OAuth2 with Password and Bearer

Now let's build from the previous chapter and add the missing parts to have a complete security flow.

## Get the `username` and `password`

We are going to use **FastAPI** security utilities to get the `username` and `password`.

OAuth2 specifies that when using the "password flow" (that we are using) the client/user must send a `username` and `password` fields as form data.

Nils Lindemann <******@****.***> 1711822124 +0100

DoHyun Kim <******@****.***> 1712097443 +0900

Guillaume Nodet <******@****.***> 1711363801 +0100

Nils Lindemann <******@****.***> 1713469999 +0200

Nils Lindemann <******@****.***> 1713469999 +0200

   */
  public void testCharacterSimpleSplitToList() {
    String simple = "a,b,c";
    List<String> letters = COMMA_SPLITTER.splitToList(simple);
    assertThat(letters).containsExactly("a", "b", "c").inOrder();
  }

  public void testCharacterSimpleSplitToStream() {
    String simple = "a,b,c";
    List<String> letters = COMMA_SPLITTER.splitToStream(simple).collect(toImmutableList());

  }

  public void testStringSimpleSplit() {
    String simple = "a,b,c";
    Iterable<String> letters = Splitter.on(",").split(simple);
    assertThat(letters).containsExactly("a", "b", "c").inOrder();
  }

  public void testStringSimpleSplitWithNoDelimiter() {
    String simple = "a,b,c";
    Iterable<String> letters = Splitter.on(".").split(simple);
    assertThat(letters).containsExactly("a,b,c").inOrder();
  }

    assertEquals(ImmutableList.<Integer>of(), result);
  }

  public void testLeastOfIterable_simple_negativeOne() {
    try {
      numberOrdering.leastOf(Arrays.asList(3, 4, 5, -1), -1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testLeastOfIterator_simple_negativeOne() {
    try {
      numberOrdering.leastOf(Iterators.forArray(3, 4, 5, -1), -1);
      fail();

    assertEquals(ImmutableList.<Integer>of(), result);
  }

  public void testLeastOfIterable_simple_negativeOne() {
    try {
      numberOrdering.leastOf(Arrays.asList(3, 4, 5, -1), -1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  public void testLeastOfIterator_simple_negativeOne() {
    try {
      numberOrdering.leastOf(Iterators.forArray(3, 4, 5, -1), -1);
      fail();