packages/kirki-framework/module-css/src/Output.php
protected function process_property_value( $property, $value ) {
		$properties = apply_filters(
			'kirki_output_property_classnames',
			[
				'font-family'         => '\Kirki\Modules\CSS\Property\Font_Family',
				'background-image'    => '\Kirki\Modules\CSS\Property\Background_Image',
				'background-position' => '\Kirki\Modules\CSS\Property\Background_Position',
			]
		);
		if ( array_key_exists( $property, $properties ) ) {
			$classname = $properties[ $property ];
			$obj       = new $classname( $property, $value );
			return $obj->get_value();
		}
		return $value;
	}
protected function process_property_value( $property, $value ) {
		$properties = apply_filters(
			'kirki_output_property_classnames',
			[
				'font-family'         => '\Kirki\Modules\CSS\Property\Font_Family',
				'background-image'    => '\Kirki\Modules\CSS\Property\Background_Image',
				'background-position' => '\Kirki\Modules\CSS\Property\Background_Position',
			]
		);
		if ( array_key_exists( $property, $properties ) ) {
			$classname = $properties[ $property ];
			$obj       = new $classname( $property, $value );
			return $obj->get_value();
		}
		return $value;
	}
protected function process_property_value ( $ property , $ value ) { $ properties = apply_filters ( 'kirki_output_property_classnames' , [ 'font-family' => '\Kirki\Modules\CSS\Property\Font_Family' , 'background-image' => '\Kirki\Modules\CSS\Property\Background_Image' , 'background-position' => '\Kirki\Modules\CSS\Property\Background_Position' , ] ) ; if ( array_key_exists ( $ property , $ properties ) ) { $ classname = $ properties [ $ property ] ; $ obj = new $ classname ( $ property , $ value ) ; return $ obj -> get_value ( ) ; } return $ value ; }
Some CSS properties are unique.
We need to tweak the value to make everything works as expected.

@access protected
@param string       $property The CSS property.
@param string|array $value    The value.

@return array
Some CSS properties are unique . We need to tweak the value to make everything works as expected .