copy method
Creates a shallow copy of this parser.
Overridden in subclasses to return an instance of the specific parser type.
Implementation
@override
SequenceParser5<R1, R2, R3, R4, R5> copy() =>
SequenceParser5<R1, R2, R3, R4, R5>(
parser1,
parser2,
parser3,
parser4,
parser5,
);