src/properties/class-papi-property-bool.php
public function format_value( $value, $slug, $post_id ) {
		if ( is_string( $value ) && $value === 'false' || $value === false ) {
			return false;
		}

		return  is_string( $value ) &&
			( $value === 'true' || $value === 'on' ) ||
			$value === true;
	}
public function format_value( $value, $slug, $post_id ) {
		if ( is_string( $value ) && $value === 'false' || $value === false ) {
			return false;
		}

		return  is_string( $value ) &&
			( $value === 'true' || $value === 'on' ) ||
			$value === true;
	}
Format the value of the property before it's returned
to WordPress admin or the site.

@param  mixed  $value
@param  string $slug
@param  int    $post_id

@return bool