@Override
	protected int adjustSeekIndex(int i) {
		return nextTokenOnChannel(i, channel);
	}
Constructs a new {@link CommonTokenStream} using the specified token
source and filtering tokens to the specified channel. Only tokens whose
{@link Token#getChannel} matches {@code channel} or have the
{@link Token#getType} equal to {@link Token#EOF} will be returned by the
token stream lookahead methods.

@param tokenSource The token source.
@param channel The channel to use for filtering tokens.
runtime/Java/src/org/antlr/v4/runtime/CommonTokenStream.java