Marcin Grzejszczak is an experienced Java programmer. He is enthusiastic about clean coding and good design. He has contributed to several open source projects (Drools, Moco, Mockito, Spock, and so on) and to Groovy core. He is the co-organizer of the Warsaw Groovy User Group. He is a member of the Most Valuable Blogger program at DZone and Java Code Geeks. Marcin is the author of Instant Mockito, Packt Publishing, and Drools Refcard at DZone. You can visit his blog,http://toomuchcoding.blogspot.com, or his home page, http://www.marcin.grzejszczak.pl. Or, you can follow him on Twitter at http://twitter.com/MGrzejszczak.