+ `flags` and `path` are exclusive.
+
+ Argument `converters` is a dictionary which updates the
+ DEFAULT_CONVERTERS to convert journal field values. Field
+ names are used as keys into this dictionary. The values must
+ be single argument functions, which take a `bytes` object and
+ return a converted value. When there's no entry for a field
+ name, then the default UTF-8 decoding will be attempted. If
+ the conversion fails with a ValueError, unconverted bytes
+ object will be returned. (Note that ValueEror is a superclass
+ of UnicodeDecodeError).
+
+ Reader implements the context manager protocol: the journal
+ will be closed when exiting the block.