code: function filterConditionalStatements(rule) {
        return _.filter(rule.ruleConditionalStatements, function(ruleCondStatement) {
          var sourceField = ruleCondStatement.sourceField.toString();
  
          if (invalidFields[sourceField]) {
            /**
             * If the user flagged the field in this rule for deletion, flag the rule for deletion.
             */
            if (ruleDeletionFlags[sourceField]) {
              rulesFlaggedForDeletion[rule._id.toString()] = true;
            }
            return false;
          } else {
            return true;
          }
        });
      }
docs: Filters out any conditional statements that are no longer valid.