code: @Required
      public void setDescriptors(final IPersonAttributes descriptors) {
  
          // Assertions.
          if (descriptors == null) {
              final String msg = "Argument 'descriptors' cannot be null";
              throw new IllegalArgumentException(msg);
          }
  
          this.descriptors = descriptors;
  
          if (this.logger.isDebugEnabled()) {
              this.logger.debug("invoking setDescriptors(" + descriptors + ")");
          }
  
      }
docs: Called by Spring DI to inject the collection of additional descriptors.
  Descriptors are user specific, and (therefore) the <code>Map</code> must
  be a session-scoped bean.
  
  @param descriptors Additional descriptors