# File lib/fog/aws/requests/lambda/update_event_source_mapping.rb, line 23
        def update_event_source_mapping(params={})
          function_name = params.delete('FunctionName')
          mapping_id    = params.delete('UUID')

          batch_size = params.delete('BatchSize')
          enabled    = params.delete('Enabled')

          update = {}
          update.merge!('BatchSize'    => batch_size)    if batch_size
          update.merge!('Enabled'      => enabled)       if !enabled.nil?
          update.merge!('FunctionName' => function_name) if function_name

          request({
            :method  => 'PUT',
            :path    => "/event-source-mappings/#{mapping_id}",
            :expects => 202,
            :body    => Fog::JSON.encode(update)
          }.merge(params))
        end