class Net::IMAP::MailboxQuota
capability.
Requires QUOTA
[RFC2087]
== Required capability
and MailboxQuota objects.
Net::IMAP#getquotaroot returns an array containing both MailboxQuotaRoot
IMAP#getquota returns an array of MailboxQuota objects.
MailboxQuota represents the data of an untagged QUOTA
response.