# File lib/fog/aws/models/rds/security_group.rb, line 59
        def revoke_ec2_security_group(group_name, group_owner_id=owner_id)
          key = group_name.match(/^sg-/) ? 'EC2SecurityGroupId' : 'EC2SecurityGroupName'
          revoke_ingress({
            key                       => group_name,
            'EC2SecurityGroupOwnerId' => group_owner_id
          })
        end