code: @Override
      protected String computeContextPath(
              final IExpressionContext context, final String base, final Map<String, Object> parameters) {
  
          if (!(context instanceof ISpringWebFluxContext)) {
              throw new TemplateProcessingException(
                      "Link base \"" + base + "\" cannot be context relative (/...) unless the context " +
                      "used for executing the engine implements the " + ISpringWebFluxContext.class.getName() + " interface");
          }
  
          // If it is context-relative, it has to be a Spring WebFlux-based context
          final ServerHttpRequest request = ((ISpringWebFluxContext)context).getRequest();
          return request.getPath().contextPath().value();
  
      }
docs: <p>
  Compute the context path to be applied to URLs that have been determined to be context-relative (and therefore
  might need a context path to be inserted at their beginning).
  </p>
  <p>
  This method will obtain the context path from {@code ServerHttpRequest.getContextPath()},
  throwing an exception if {@code context} is not an instance of {@code ISpringWebFluxContext} given
  context-relative URLs are (by default) only allowed in Spring WebFlux contexts.
  </p>
  <p>
  This method can be overridden by any subclasses that want to change this behaviour.
  </p>
  
  @param context the execution context.
  @param base the URL base specified.
  @param parameters the URL parameters specified.
  @return the context path.