An exception used to indicate errors in a regular expression fetched
from a PatternCache.
It is derived from RuntimeException, and therefore does not have to be
caught. You should generally make an effort to catch
MalformedCachePatternException whenever you use dynamically generated
patterns (from user input or some other source). Static expressions
represented as strings in your source code don't require exception
handling because as you write and test run your program you will
correct any errors in those expressions when you run into an uncaught
MalformedCachePatternException. By the time you complete your
project, those static expressions will be guaranteed to be correct.
However, pieces of code with expressions that you cannot guarantee to
be correct should catch MalformedCachePatternException to ensure
reliability.
