class SimpleIndentStrategy implements Function<Integer, String> {

	private final String indent;

	/**
	 * Create a new instance with the indent style to apply.
	 * @param indent the indent to apply for each indent level
	 */
	public SimpleIndentStrategy(String indent) {
		Assert.notNull(indent, "Indent must be provided");
		this.indent = indent;
	}

	@Override
	public String apply(Integer level) {<FILL_FUNCTION_BODY>}

}

		if (level < 0) {
			throw new IllegalArgumentException("Indent level must not be negative, got" + level);
		}
		return String.valueOf(this.indent).repeat(level);
	
<no_super_class>