code: @Required
      public void setLocation(final String location) {
  
          // Assertions.
          if (location == null) {
              String msg = "Argument 'location' cannot be null.";
              throw new IllegalArgumentException(msg);
          }
          if (this.location != null) {
              String msg = "Property 'location' may only be set once.";
              throw new RuntimeException(msg);
          }
  
          this.location = location;
  
      }
docs: Sets the <code>location</code> URL from which Cernunnos XML will be read
  to create this task.  A relative <code>location</code> will be evaluated
  from the <code>context</code> URL.  This method must be called exactly
  once.
  
  @param location Absolute or relative location of the Cernunnos XML for
  this task