$co_author = Array
(
    [ID] => 98
    [user_firstname] => Francesca
    [user_lastname] => Caminiti
    [nickname] => francesca.caminiti
    [user_nicename] => francesca-caminiti
    [display_name] => Francesca Caminiti
    [user_email] => francesca.caminiti@accenture.com
    [user_url] => 
    [user_registered] => 2019-02-05 22:48:24
    [user_description] => 
    [user_avatar] => 
)