This class is part of the ScalaTest matchers DSL. Please see the documentation for Matchers for an overview of
the matchers DSL.
This class is used in conjunction with an implicit conversion to enable withGroup and withGroups methods to
be invoked on Regexs.
This method enables syntax such as the following:
regex must fullyMatch regex ("a(b*)c" withGroup "bb")
regex must fullyMatch regex ("a(b*)(c*)" withGroups ("bb", "cc"))