code: function addValidChildren(validChildren) {
                  var childRuleRegExp = /^([+\-]?)(\w+)\[([^\]]+)\]$/;
                  // Invalidate the schema cache if the schema is mutated
                  mapCache[settings.schema] = null;
                  validChildren && each(split(validChildren, ','), function(rule) {
                      var parent, prefix, matches = childRuleRegExp.exec(rule);
                      if (matches) {
                          prefix = matches[1];
                          // Add/remove items from default
                          parent = prefix ? children[matches[2]] : children[matches[2]] = {
                              '#comment': {}
                          };
                          parent = children[matches[2]];
                          each(split(matches[3], '|'), function(child) {
                              '-' === prefix ? delete parent[child] : parent[child] = {};
                          });
                      }
                  });
              }
docs: Adds valid children to the schema object