how to get effect sizes after using the command "xtreg" in Stata 14

Dear Statalisters,

I'm trying to use Stata 14 to get effect sizes after using the command "xtreg". When the command is 'regress', I'm able to follow it with 'estat esize' to get partial eta squared effect sizes for each term. However, with xtreg I get an error:
. estat esize
invalid subcommand esize
What command can I use to get effect sizes using xtreg, or what am I missing? Thank you!