public function getListStyleFields()
    {
        // Obtain Field Objects (from parent):
        
        $fields = parent::getListStyleFields();
        
        // Create Field Objects:
        
        $fields->merge([
            FieldSection::create(
                'MasonryStyle',
                $this->fieldLabel('MasonryStyle'),
                [
                    SelectionGroup::create(
                        'ColumnUnit',
                        [
                            SelectionGroup_Item::create(
                                self::UNIT_PERCENT,
                                ViewportsField::create(
                                    'PercentWidth',
                                    ''
                                )->setUseTextInput(true),
                                $this->owner->fieldLabel('Percentages')
                            ),
                            SelectionGroup_Item::create(
                                self::UNIT_PIXEL,
                                ViewportsField::create(
                                    'PixelWidth',
                                    ''
                                )->setUseTextInput(true),
                                $this->owner->fieldLabel('Pixels')
                            )
                        ]
                    )->setTitle($this->owner->fieldLabel('ColumnWidths')),
                    TextField::create(
                        'Gutter',
                        $this->fieldLabel('Gutter')
                    )
                ]
            )
        ]);
        
        // Answer Field Objects:
        
        return $fields;
    }