## Type hints en **FastAPI**

**FastAPI** aprovecha estos type hints para hacer varias cosas.

Con **FastAPI** declaras los parámetros con type hints y obtienes:

* **Soporte en el editor**.
* **Type checks**.

...y **FastAPI** usa las mismas declaraciones para:

* **Definir requerimientos**: desde request path parameters, query parameters, headers, bodies, dependencies, etc.

      @CheckForNull Type ownerType, Class<?> rawType, Type... arguments) {
    if (ownerType == null) {
      return newParameterizedType(rawType, arguments);
    }
    // ParameterizedTypeImpl constructor already checks, but we want to throw NPE before IAE
    checkNotNull(arguments);
    checkArgument(rawType.getEnclosingClass() != null, "Owner type for unenclosed %s", rawType);
    return new ParameterizedTypeImpl(ownerType, rawType, arguments);

  /**
   * The current state of the service. This should be written with the lock held but can be read
   * without it because it is an immutable object in a volatile field. This is desirable so that
   * methods like {@link #state}, {@link #failureCause} and notably {@link #toString} can be run
   * without grabbing the lock.
   *
   * <p>To update this field correctly the lock must be held to guarantee that the state is
   * consistent.
   */

     * implement Function<A, B>, as discussed in a class-level comment), it would make some sense to
     * perform runtime null checks on the input and output. (That would also make NullPointerTester
     * happy!) However, since we didn't do that for many years, we're not about to start now.
     * (Runtime checks could be particularly bad for users of LegacyConverter.)
     *

      accum /= i + 1;
    }
    return accum;
  }

  @GwtIncompatible // java.math.BigInteger
  public void testIsPowerOfTwo() {
    for (long x : ALL_LONG_CANDIDATES) {
      // Checks for a single bit set.
      BigInteger bigX = BigInteger.valueOf(x);
      boolean expected = (bigX.signum() > 0) && (bigX.bitCount() == 1);
      assertEquals(expected, LongMath.isPowerOfTwo(x));
    }
  }

    distinctValues.replaceValues(type, ImmutableList.of(value1, value2));
    setDefault(type, value1);
    return this;
  }

  /**
   * Tests that {@code cls} properly checks null on all constructor and method parameters that
   * aren't annotated nullable (according to the rules of {@link NullPointerTester}). In details:
   *
   * <ul>

   */
  public ByteSource slice(long offset, long length) {
    return new SlicedByteSource(offset, length);
  }

  /**
   * Returns whether the source has zero bytes. The default implementation first checks {@link
   * #sizeIfKnown}, returning true if it's known to be zero and false if it's known to be non-zero.
   * If the size is not known, it falls back to opening a stream and checking for EOF.
   *

      private val useCompression: Boolean = true,
      private val out: Buffer,
    ) {
      /**
       * In the scenario where the dynamic table size changes multiple times between transmission of
       * header blocks, we need to keep track of the smallest value in that interval.
       */
      private var smallestHeaderTableSizeSetting = Integer.MAX_VALUE
      private var emitDynamicTableSizeUpdate: Boolean = false

  for (i in 0 until length) {
    val c = this[i]
    // The WHATWG Host parsing rules accepts some character codes which are invalid by
    // definition for OkHttp's host header checks (and the WHATWG Host syntax definition). Here
    // we rule out characters that would cause problems in host headers.
    if (c <= '\u001f' || c >= '\u007f') {
      return true
    }

    }

    @Override
    public MavenSession clone() {
        try {
            MavenSession clone = (MavenSession) super.clone();
            // the default must become the current project of the thread that clones this
            MavenProject current = getCurrentProject();
            // we replace the thread local of the clone to prevent write through and enforce the new default value