* regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an

        return doGet(userProperties != null ? userProperties.get(key) : null, def);
    }

    private static boolean doGet(Object val, boolean def) {
        if (val instanceof Boolean bool) {
            return bool;
        } else if (val != null) {
            return Boolean.parseBoolean(val.toString());
        } else {
            return def;
        }
    }

/*
 * Copyright 2020 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2024 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

        return gson.toJson(subprojects) + '\n'
    }

    private
    fun generateSubprojectsDirectories(): List<File> {
        val subprojectRoots = platformsFolder.asFile.listFiles(File::isDirectory)
            .plus(subprojectsFolder.asFile)
            .plus(testingFolder.asFile)
            .plus(packingFolder.asFile)

    }

    String getId() {
        return id
    }

    String getName() {
        return name
    }

    PropertyMetaData getMetaData() {
        return metaData
    }

    boolean isDeprecated() {
        return metaData.deprecated && !referringClass.deprecated
    }

    boolean isIncubating() {
        return metaData.incubating || metaData.ownerClass.incubating
    }

        }
        return systemProperties
    }

    private
    fun getStudioHome(): String {
        if (autoDownloadAndroidStudio) {
            val androidStudioPath = studioInstallation.studioInstallLocation.asFile.get().absolutePath
            return "-Dstudio.home=$androidStudioPath"
        } else if (androidStudioHome.isPresent) {
            return "-Dstudio.home=${androidStudioHome.get()}"
        }

Beginnen wir mit einem Beispiel und sehen es uns dann im Detail an.

Wir erstellen eine asynchrone Funktion `lifespan()` mit `yield` wie folgt:

{* ../../docs_src/events/tutorial003_py39.py hl[16,19] *}

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,

/*
 * Copyright 2012-2025 CodeLibs Project and the Others.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,