Adds extra CSS styles to a registered stylesheet.

Processes items and dependencies for the footer group.

Prints extra CSS styles of a registered stylesheet.

Resets class properties.

Magic method for accessing custom fields.

Magic method for checking the existence of a certain custom field.

Magic method for setting custom user fields.

Retrieves the value of a property or meta key.

Returns only the main user fields.

Determines whether a property or meta key is set.