Support › Meta Box Group › Escaping and Sanitization
The sanitize and esc_meta methods don't actually do anything and needs to be fixed before I can use it. Since this isn't a public extension I don't want to maintain any changes.
The sanitize method removes all empty values in the group. Empty values are empty string and empty array.
The esc_meta simply overwrites parent's method, to make the value of sub-fields not escaped.
They're not bugs and no need to fix them.