This class is a special CodeReaderFilter that uses Channels to filter the character stream before it is passed to the main channels
declared for the CodeReader.
The consume method is called each time the regular expression used to create the RegexChannel object matches the next characters in the
character streams.
This method implements the filtering logic, that is:
get the characters from the reader,
filter the character flow (and grab more characters from the reader if the filtering removes some),
and fill the given buffer to its full capacity with the filtered data.
This method implements the filtering logic, that is:
get the characters from the reader,
filter the character flow (and grab more characters from the reader if the filtering removes some),
and fill the given buffer to its full capacity with the filtered data.