private void indent(int levels, String indentText) {
            // Set to Integer.MIN_VALUE to indent back to root.
            if (levels == Integer.MIN_VALUE) {
                indentation = 0;
            } else if (levels + indentation < 0) {
                throw new IllegalStateException(String.format("Cannot dedent writer %d levels", levels));
            } else {
                indentation += levels;
            }

            if (indentText != null) {
                this.indentText = indentText;
            }

            leadingIndentString = StringUtils.repeat(this.indentText, indentation);
        }
Inline states are created when formatting text. They aren't written
directly to the AbstractCodeWriter, but rather captured as part of the
process of expanding a template argument.
smithy-utils/src/main/java/software/amazon/smithy/utils/AbstractCodeWriter.java