Sets the anchoring of region bounds for this matcher.
Invoking this method with an argument of true will set this matcher to use anchoring bounds. If the boolean argument is false, then non-anchoring bounds will be used.
Using anchoring bounds, the boundaries of this matcher's region match anchors such as ^ and $.
Without anchoring bounds, the boundaries of this matcher's region will not match anchors such as ^ and $.
By default, a matcher uses anchoring region boundaries.
@param b a boolean indicating whether or not to use anchoring bounds.
@return this matcher
@see java.util.regex.Matcher#hasAnchoringBounds
@since 1.5