Test leaving target_type alone for other field types that may have set it.
public function testTaxonomyParagraphFieldSettings() {
$this->row
->expects($this
->any())
->method('getSourceProperty')
->with('type')
->willReturn('taxonomy_term');
$value = $this->plugin
->transform([
'target_type' => 'some_preset_vaue',
], $this->migrateExecutable, $this->row, 'settings');
$this
->assertEquals([
'target_type' => 'some_preset_vaue',
], $value);
}