Aggregate option explain is incompatible with the explain command

The 'explain' option is illegal when a explain verbosity is also provided

Author: GromNaN

src/Operation/Aggregate.php

@@ -300,6 +300,10 @@ public function getCommandDocument()
     {
         $cmd = $this->createCommandDocument();
 
+        // The 'explain' option is incompatible with the explain command
+        unset($cmd['explain']);
+        unset($cmd['cursor']);
+
         // Read concern can change the query plan
         if (isset($this->options['readConcern'])) {
             $cmd['readConcern'] = $this->options['readConcern'];

tests/Operation/AggregateTest.php

@@ -2,6 +2,9 @@
 
 namespace MongoDB\Tests\Operation;
 
+use MongoDB\Driver\ReadConcern;
+use MongoDB\Driver\ReadPreference;
+use MongoDB\Driver\WriteConcern;
 use MongoDB\Exception\InvalidArgumentException;
 use MongoDB\Operation\Aggregate;
 
@@ -104,4 +107,40 @@ private function getInvalidHintValues()
     {
         return [123, 3.14, true];
     }
+
+    public function testExplainableCommandDocument(): void
+    {
+        $options = [
+            'allowDiskUse' => true,
+            'batchSize' => 100,
+            'bypassDocumentValidation' => true,
+            'collation' => ['locale' => 'fr'],
+            'comment' => 'explain me',
+            'hint' => '_id_',
+            'let' => ['a' => 1],
+            'maxTimeMS' => 100,
+            'readConcern' => new ReadConcern(ReadConcern::LOCAL),
+            'useCursor' => true,
+            // Intentionally omitted options
+            'explain' => true,
+            'readPreference' => new ReadPreference(ReadPreference::SECONDARY_PREFERRED),
+            'typeMap' => ['root' => 'array', 'document' => 'array'],
+            'writeConcern' => new WriteConcern(0),
+        ];
+        $operation = new Aggregate($this->getDatabaseName(), $this->getCollectionName(), [['$project' => ['_id' => 0]]], $options);
+
+        $expected = [
+            'aggregate' => $this->getCollectionName(),
+            'pipeline' => [['$project' => ['_id' => 0]]],
+            'allowDiskUse' => true,
+            'bypassDocumentValidation' => true,
+            'collation' => (object) ['locale' => 'fr'],
+            'comment' => 'explain me',
+            'hint' => '_id_',
+            'maxTimeMS' => 100,
+            'readConcern' => new ReadConcern(ReadConcern::LOCAL),
+            'let' => (object) ['a' => 1],
+        ];
+        $this->assertEquals($expected, $operation->getCommandDocument());
+    }
 }

tests/Operation/DistinctTest.php

@@ -4,7 +4,6 @@
 
 use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
-use MongoDB\Driver\WriteConcern;
 use MongoDB\Exception\InvalidArgumentException;
 use MongoDB\Operation\Distinct;