Gate theatre, DublinDirected by RóisÃn McBrinn, this 2009 play is an absorbing study of group dynamics, deepened by intricate dialogue and superb acting Six weeks is a long time in theatre, as a group of strangers discover when they come together for a drama class in Annie Baker's ensemble play from 2009. This American playwright has since been acclaimed for work including The Flick, John and The Antipodes, and…