code: function(known) {
          if (known) {
              return childrenSpec
                  .filter(function(x) {
                      return (that.$[x.name] !== undefined);
                  })
                  .map(function(x) { return x.name;});
          } else {
              return Object.keys(that.$)
                  .filter(function(x) {
                      return ((x !== naming.TOP) && (x !== naming.CA) &&
                              (x !== naming.LOADER) &&
                              (!that.$[x].__ca_isNotUnknown__) &&
                              (childrenSpecObj[x] === undefined));
                  });
          }
      }
docs: /*
  Filter current children based on whether they are expected.
  
  @param {boolean} known True if we want to select present and expected
  children, false if present and unexpected.
  
  @return {Array.<string>} Names of the selected children.