10 files declare their use of FileExistsException
- CopyTest.php in core/
modules/ file/ tests/ src/ Kernel/ CopyTest.php  - file.module in core/
modules/ file/ file.module  - Defines a "managed_file" Form API field and a "file" field for Field module.
 - FileCopyTest.php in core/
tests/ Drupal/ KernelTests/ Core/ File/ FileCopyTest.php  - FileRepositoryTest.php in core/
modules/ file/ tests/ src/ Kernel/ FileRepositoryTest.php  - FileSystem.php in core/
lib/ Drupal/ Core/ File/ FileSystem.php  - FileSystemTest.php in core/
tests/ Drupal/ KernelTests/ Core/ File/ FileSystemTest.php  - FileUpload.php in core/
modules/ jsonapi/ src/ Controller/ FileUpload.php  - FileUploadHandler.php in core/
modules/ file/ src/ Upload/ FileUploadHandler.php  - FileUploadResource.php in core/
modules/ file/ src/ Plugin/ rest/ resource/ FileUploadResource.php  - MoveTest.php in core/
modules/ file/ tests/ src/ Kernel/ MoveTest.php  
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