the main features needed by API systems is data "<abbr title="also called marshalling, conversion">serialization</abbr>" which is taking data from the code (Python) and converting it into something that can be sent through the network. For example, converting an object containing data from a database into a JSON object. Converting `datetime` objects into strings, etc.

Another big feature needed by APIs is data validation, making sure that the data is valid, given certain parameters. For...

/// danger

This is an "advanced" feature.

If you are just starting with **FastAPI** you might want to skip this section.

///

## Use cases { #use-cases }

Some use cases include:

* Converting non-JSON request bodies to JSON (e.g. <a href="https://msgpack.org/index.html" class="external-link" target="_blank">`msgpack`</a>).
* Decompressing gzip-compressed request bodies.
* Automatically logging all request bodies.

You should never save plaintext passwords, so, we'll use the (fake) password hashing system.

If the passwords don't match, we return the same error.

#### Password hashing { #password-hashing }

"Hashing" means: converting some content (a password in this case) into a sequence of bytes (just a string) that looks like gibberish.

Whenever you pass exactly the same content (exactly the same password) you get exactly the same gibberish.

     */
    checkState(future.isDone(), "Future was expected to be done: %s", future);
    return getUninterruptibly(future);
  }

  /**
   * Returns the result of {@link Future#get()}, converting most exceptions to a new instance of the
   * given checked exception type. This reduces boilerplate for a common use of {@code Future} in

                    ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ', ' ' };

    /**
     * Array of hexadecimal digit characters used for converting binary data to hex representation.
     */
    public static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };

    /**

  fun hostContainsOnlyStrippedCharacters() {
    val url = "http://>/".toHttpUrl()
    assertThat(url.host).isEqualTo(">")
    assertThat(url.toUri().host).isNull()
  }

  /**
   * Strip unexpected characters when converting to URI (which is more strict).
   * https://github.com/square/okhttp/issues/5667
   */
  @Test
  fun hostToUriStripsCharacters() {
    val httpUrl = "http://example\".com/".toHttpUrl()

        assertEquals("BUILTIN", sid.getDomainName());
        assertEquals("Administrators", sid.getAccountName());
        assertEquals(adminSidString, sid.toString());
    }

    /**
     * Test converting a SID to a byte array.
     */
    @Test
    void testToByteArray() {
        SID sid = new SID(adminSidBytes, 0);
        assertArrayEquals(adminSidBytes, sid.toByteArray());
    }

    /**

 * limitations under the License.
 */
package okhttp3.internal.idn

import okio.Buffer
import okio.ByteString.Companion.encodeUtf8

/**
 * An [RFC 3492] punycode decoder for converting ASCII to Unicode domain name labels. This is
 * intended for use in Internationalized Domain Names (IDNs).
 *
 * This class contains a Kotlin implementation of the pseudocode specified by RFC 3492. It includes

        void testNullMechanisms() {
            NegTokenInit init = new NegTokenInit(null, 0, null, null);
            assertNull(init.getMechanisms());

            // Should not throw when converting to byte array
            assertDoesNotThrow(() -> init.toByteArray());
        }

        @Test
        @DisplayName("Large MIC values are handled correctly")
        void testLargeMicValue() throws Exception {

    consistent with the length of the response body.

 *  Fix: Don't crash when converting a `HttpUrl` instance with an unresolvable hostname to a URI.
    The new behavior strips invalid characters like `"` and `{` from the hostname before converting.

 *  Fix: Undo a performance regression introduced in OkHttp 4.0 caused by differences in behavior