code: public final RenderConfiguration cloneAndChangeIndentation(final int indentationChange)
              throws IllegalArgumentException {
  
          // Check sanity
          final int newIndentationLevel = getIndentationLevel() + indentationChange;
          final RenderConfiguration toReturn = new RenderConfiguration(
                  newIndentationLevel,
                  indentationToken,
                  isDirectedGraph);
  
          toReturn.getExtraConfiguration().putAll(getExtraConfiguration());
  
          // All Done.
          return toReturn;
      }
docs: Clones this RenderConfiguration, and changes the indentation level (of the returned
  RenderConfiguration) as indicated.
  
  @param indentationChange The change of the indentation level in the returned RenderConfiguration.
  @return A {@link RenderConfiguration} clone of this one - except that the indentationLevel is changed with the
  supplied amount.
  @throws IllegalArgumentException if the indentationLevel after the change is negative.
  @see #setIndentationLevel(int)