Fix error when headers option to Csv resource task is null

Author: clever-age-gtonon

src/Filesystem/CsvResource.php

@@ -42,7 +42,7 @@ class CsvResource implements WritableStructuredFileInterface, SeekableFileInterf
 
     protected ?int $lineNumber = 1;
 
-    protected bool $closed;
+    protected bool $closed = false;
 
     protected bool $seekCalled = false;
 

src/Task/File/Csv/AbstractCsvResourceTask.php

@@ -63,5 +63,5 @@ protected function configureOptions(OptionsResolver $resolver): void
         $resolver->setAllowedTypes('headers', ['null', 'array']);
     }
 
-    abstract protected function getHeaders(ProcessState $state, array $options): array;
+    abstract protected function getHeaders(ProcessState $state, array $options): ?array;
 }

src/Task/File/Csv/CsvReaderTask.php

@@ -78,7 +78,7 @@ public function next(ProcessState $state): bool
         return ! $this->csv->isEndOfFile();
     }
 
-    protected function getHeaders(ProcessState $state, array $options): array
+    protected function getHeaders(ProcessState $state, array $options): ?array
     {
         return $options['headers'];
     }

src/Task/File/Csv/CsvWriterTask.php

@@ -85,7 +85,7 @@ protected function getInput(ProcessState $state): array
         return $input;
     }
 
-    protected function getHeaders(ProcessState $state, array $options): array
+    protected function getHeaders(ProcessState $state, array $options): ?array
     {
         $headers = $options['headers'];
         if ($headers === null) {