public static LexerActionExecutor append(LexerActionExecutor lexerActionExecutor, LexerAction lexerAction) {
		if (lexerActionExecutor == null) {
			return new LexerActionExecutor(new LexerAction[] { lexerAction });
		}

		LexerAction[] lexerActions = Arrays.copyOf(lexerActionExecutor.lexerActions, lexerActionExecutor.lexerActions.length + 1);
		lexerActions[lexerActions.length - 1] = lexerAction;
		return new LexerActionExecutor(lexerActions);
	}
Creates a {@link LexerActionExecutor} which executes the actions for
the input {@code lexerActionExecutor} followed by a specified
{@code lexerAction}.

@param lexerActionExecutor The executor for actions already traversed by
the lexer while matching a token within a particular
{@link LexerATNConfig}. If this is {@code null}, the method behaves as
though it were an empty executor.
@param lexerAction The lexer action to execute after the actions
specified in {@code lexerActionExecutor}.

@return A {@link LexerActionExecutor} for executing the combine actions
of {@code lexerActionExecutor} and {@code lexerAction}.
runtime/Java/src/org/antlr/v4/runtime/atn/LexerActionExecutor.java