18 files declare their use of PublicStream

CachedStorageTest.php in core/tests/Drupal/KernelTests/Core/Config/Storage/CachedStorageTest.php
DummyRemoteStreamWrapper.php in core/modules/file/tests/file_test/src/StreamWrapper/DummyRemoteStreamWrapper.php
FileStorageTest.php in core/tests/Drupal/KernelTests/Core/Config/Storage/FileStorageTest.php
FileSystem.php in core/lib/Drupal/Core/File/FileSystem.php
FileSystemForm.php in core/modules/system/src/Form/FileSystemForm.php
FileTransferTest.php in core/modules/system/tests/src/Functional/FileTransfer/FileTransferTest.php
FilterHtmlImageSecureTest.php in core/modules/filter/tests/src/Functional/FilterHtmlImageSecureTest.php
ImageStyleCustomStreamWrappersTest.php in core/modules/image/tests/src/Kernel/ImageStyleCustomStreamWrappersTest.php
LocaleTranslationDownloadTest.php in core/modules/locale/tests/src/Functional/LocaleTranslationDownloadTest.php
LocaleUpdateBase.php in core/modules/locale/tests/src/Functional/LocaleUpdateBase.php
locale_test.module in core/modules/locale/tests/modules/locale_test/locale_test.module
Simulate a custom module with a local po file.
PhpStorageFactory.php in core/lib/Drupal/Core/PhpStorage/PhpStorageFactory.php
PhpStorageFactoryTest.php in core/modules/system/tests/src/Kernel/PhpStorage/PhpStorageFactoryTest.php
StreamWrapperTest.php in core/tests/Drupal/KernelTests/Core/File/StreamWrapperTest.php
system.install in core/modules/system/system.install
Install, update and uninstall functions for the system module.
TestFileCreationTrait.php in core/tests/Drupal/Tests/TestFileCreationTrait.php
ThemeSettingsForm.php in core/modules/system/src/Form/ThemeSettingsForm.php
ThemeTest.php in core/modules/system/tests/src/Functional/System/ThemeTest.php

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