module Devise::Models::Lockable

def lock_access!(opts = { })

`{ send_instructions: false } as option`.
when you lock access, you could pass the next hash
* +opts+: Hash options if you don't want to send email
Lock a user setting its locked_at to actual time. 
def lock_access!(opts = { })
  self.locked_at = Time.now.utc
  if unlock_strategy_enabled?(:email) && opts.fetch(:send_instructions, true)
    send_unlock_instructions
  else
    save(validate: false)
  end
end