# File lib/AWS/EC2/instances.rb, line 184
184:       def monitor_instances( options = {} )
185:         options = { :instance_id => [] }.merge(options)
186:         raise ArgumentError, "No :instance_id provided" if options[:instance_id].nil? || options[:instance_id].empty?
187:         params = pathlist("InstanceId", options[:instance_id])
188:         return response_generator(:action => "MonitorInstances", :params => params)
189:       end