private void writePointer(int numberLength, int cursorColumn) {
        writer.style(w -> {
            for (int j = 0; j < numberLength; j++) {
                w.append(' ');
            }
            w.append("|");
        }, ColorTheme.MUTED);

        for (int j = 0; j < cursorColumn; j++) {
            writer.append(' ');
        }
        writer.print("^", ColorTheme.ERROR);
        writer.println();
    }
Formats source {@link SourceContextLoader.Line} values and writes them to an {@link Appendable}.
smithy-cli/src/main/java/software/amazon/smithy/cli/commands/CodeFormatter.java