class Net::IMAP

def capability

Related: #capable?, #auth_capable?, #capability, #enable

See Net::IMAP@Capabilities for more about \IMAP capabilities.

sending the #capability command unnecessarily.
Use #capable?, #auth_capable?, or #capabilities to this cache and avoid
{§7.1}[https://www.rfc-editor.org/rfc/rfc9051#section-7.1].
{§6.2}[https://www.rfc-editor.org/rfc/rfc9051#section-6.2], and
{IMAP4rev2 §6.1.1}[https://www.rfc-editor.org/rfc/rfc9051#section-6.1.1],
the requirements and recommendations in
Net::IMAP automatically stores and discards capability data according to

behaviour according to the server's advertised #capabilities.
*NOTE:* Most Net::IMAP methods do not _currently_ modify their

The result is stored for use by #capable? and #capabilities.
and returns an array of capabilities that are supported by the server.
Sends a {CAPABILITY command [IMAP4rev1 §6.1.1]}[https://www.rfc-editor.org/rfc/rfc3501#section-6.1.1] 
def capability
  synchronize do
    send_command("CAPABILITY")
    @capabilities = clear_responses("CAPABILITY").last.freeze
  end
end