# File lib/rudy/aws/ec2/group.rb, line 141
141:       def list_as_hash(group_names=[], &each_group)
142:         group_names = [group_names].flatten.compact
143:         glist = @@ec2.describe_security_groups(:group_name => group_names) || {}
144:         return unless glist['securityGroupInfo'].is_a?(Hash)
145:         groups = {}
146:         glist['securityGroupInfo']['item'].each do |oldg| 
147:           g = Groups.from_hash(oldg)
148:           groups[g.name] = g
149:         end
150:         groups.each_value { |g| each_group.call(g) } if each_group
151:         groups = nil if groups.empty?
152:         groups
153:       end