ElggEntity::deleteMetadata PHP Method

    public function deleteMetadata($name = null)
    {
        if (!$this->guid) {
            return false;
        }
        $options = array('guid' => $this->guid, 'limit' => 0);
        if ($name) {
            $options['metadata_name'] = $name;
        }
        return elgg_delete_metadata($options);
    }

 public function testElggEntityMetadata()
 {
     // let's delete a non-existent metadata
     $this->assertFalse($this->entity->deleteMetadata('important'));
     // let's add the metadata
     $this->entity->important = 'indeed!';
     $this->assertIdentical('indeed!', $this->entity->important);
     $this->entity->less_important = 'true, too!';
     $this->assertIdentical('true, too!', $this->entity->less_important);
     // test deleting incorrectly
     // @link https://github.com/elgg/elgg/issues/2273
     $this->assertNull($this->entity->deleteMetadata('impotent'));
     $this->assertEqual($this->entity->important, 'indeed!');
     // get rid of one metadata
     $this->assertEqual($this->entity->important, 'indeed!');
     $this->assertTrue($this->entity->deleteMetadata('important'));
     $this->assertNull($this->entity->important);
     // get rid of all metadata
     $this->assertTrue($this->entity->deleteMetadata());
     $this->assertNull($this->entity->less_important);
 }