**FastAPI** is all based on these type hints, they give it many advantages and benefits.

But even if you never use **FastAPI**, you would benefit from learning a bit about them.

/// note

If you are a Python expert, and you already know everything about type hints, skip to the next chapter.

///

## Motivation { #motivation }

Let's start with a simple example:

{* ../../docs_src/python_types/tutorial001.py *}

  private static int ceilToPowerOfTwo(int x) {
    return 1 << IntMath.log2(x, RoundingMode.CEILING);
  }

  /*
   * This method was written by Doug Lea with assistance from members of JCP JSR-166 Expert Group
   * and released to the public domain, as explained at
   * http://creativecommons.org/licenses/publicdomain
   *
   * As of 2010/06/11, this method is identical to the (package private) hash method in OpenJDK 7's

 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.helper;

import java.util.ArrayList;
import java.util.Collections;

		sc = objInfo.StorageClass
	}
	putOpts = minio.PutObjectOptions{
		UserMetadata:    meta,
		ContentType:     objInfo.ContentType,
		ContentEncoding: objInfo.ContentEncoding,
		Expires:         objInfo.Expires,
		StorageClass:    sc,
		Internal: minio.AdvancedPutOptions{
			SourceVersionID:    objInfo.VersionID,
			ReplicationStatus:  minio.ReplicationStatusReplica,
			SourceMTime:        objInfo.ModTime,

        byte[] encodeBuffer = new byte[1024];
        NdrBuffer dst = new NdrBuffer(encodeBuffer, 0);
        enumEx.encode_in(dst);

        // Simulate decode_out
        // The decode_out method expects the info and totalentries to be already initialized
        // and will decode into them.
        netdfs.DfsEnumStruct decodedInfo = new netdfs.DfsEnumStruct();
        NdrLong decodedTotalEntries = new NdrLong(0);

 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.crawler.transformer;

import static org.codelibs.core.stream.StreamUtil.stream;

 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.admin.storage;

import static org.codelibs.core.stream.StreamUtil.split;

 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.repository.legacy;

import javax.inject.Inject;

            }
        }

    }

    /*
     * Build a connection. Only one thread will ever call this method at
     * any one time. If this method throws an exception or the connect timeout
     * expires an encapsulating TransportException will be thrown from connect
     * and the transport will be in error.
     */

    /**
     * Establish the transport connection
     *

	if err != nil {
		return err
	}

	xhttp.DrainBody(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return errors.New(resp.Status)
	}

	return nil
}

// Expire expires object versions which have already matched supplied filter conditions
func (r *BatchJobExpire) Expire(ctx context.Context, api ObjectLayer, vc *versioning.Versioning, objsToDel []ObjectToDelete) []error {
	opts := ObjectOptions{