code: @Override
      public String getDetails(Comparison.Detail difference, ComparisonType type, boolean formatXml) {
          if (difference.getTarget() == null) {
              return "<NULL>";
          }
          return getFullFormattedXml(difference.getTarget(), type, formatXml);
      }
docs: Return the xml node from {@link Detail#getTarget()} as formatted String.
  
  <p>Delegates to {@link #getFullFormattedXml} unless the {@code Comparison.Detail}'s {@code target} is null.</p>
  
  @param difference The {@link Comparison#getControlDetails()} or {@link Comparison#getTestDetails()}.
  @param type the implementation can return different details depending on the ComparisonType.
  @param formatXml set this to true if the Comparison was generated with {@link
  org.xmlunit.builder.DiffBuilder#ignoreWhitespace()} - this affects the indentation of the generated output.
  
  @return the full xml node.