of the main features needed by API systems is data "<dfn title="also called marshalling, conversion">serialization</dfn>" 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...

    // ----------------/
    // - Constructors -/
    // ----------------/

    /**
     * Creates a new InputLocation from an API model InputLocation.
     * This constructor is used for converting between the API model and the compat model.
     *
     * @param location the API model InputLocation to convert from
     */
    public InputLocation(org.apache.maven.api.model.InputLocation location) {

    val cookie = cookies[0]
    assertThat(cookie.name).isEqualTo("a")
    assertThat(cookie.value).isEqualTo("android")
    assertThat(cookie.commentURL).isNull()
    assertThat(cookie.discard).isFalse()
    // Converting to a fixed date can cause rounding!
    assertThat(cookie.maxAge.toDouble()).isCloseTo(60.0, 5.0)
    assertThat(cookie.path).isEqualTo("/path")
    assertThat(cookie.secure).isTrue()
  }

  @Test

  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());
    }

    /**

    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

   * use {@link String#isEmpty()} instead of this method, and you won't need special null-safe forms
   * of methods like {@link String#toUpperCase} either. Or, if you'd like to normalize "in the other
   * direction," converting empty strings to {@code null}, you can use {@link #emptyToNull}.
   *
   * @param string a string reference to check
   * @return {@code true} if the string is null or is the empty string
   */

- **Bean Manipulation** (`org.codelibs.core.beans`) - JavaBeans metadata handling, property access, and object conversion with comprehensive `BeanDesc` system
- **Type Conversion** (`org.codelibs.core.convert`) - Comprehensive utilities for converting between Java types with null-safe operations and support for all primitive types

    * Path parameters.
    * Query parameters.
    * Cookies.
    * Headers.
    * Forms.
    * Files.
* <dfn title="also known as: serialization, parsing, marshalling">Conversion</dfn> of output data: converting from Python data and types to network data (as JSON):
    * Convert Python types (`str`, `int`, `float`, `bool`, `list`, etc).
    * `datetime` objects.
    * `UUID` objects.
    * Database models.

With a response model, FastAPI will use Pydantic to serialize the data to JSON, without using intermediate steps, like converting it with `jsonable_encoder`, which would happen in any other case.