code: public void setContext(final String context) {
          
          // Assertions.
          if (context == null) {
              String msg = "Argument 'context' cannot be null.";
              throw new IllegalArgumentException(msg);
          }
          if (this.context != null) {
              String msg = "Property 'context' may only be set once.";
              throw new RuntimeException(msg);
          }
          
          this.context = context;
  
      }
docs: Sets the <code>context</code> URL from which a relative
  <code>location</code> URL should be evaluated.  If <code>location</code>
  is not relative then <code>context</code> has no effect.  The default is
  the location of the <code>PojoTask.class</code> file.  This method may be
  called at most once.
  
  @param context A URL in <code>String</code> form