packages/optimizely-sdk/lib/core/condition_tree_evaluator/index.js
function notEvaluator(conditions, leafEvaluator) {
  if (conditions.length > 0) {
    var result = evaluate(conditions[0], leafEvaluator);
    return result === null ? null : !result;
  }
  return null;
}
function notEvaluator(conditions, leafEvaluator) {
  if (conditions.length > 0) {
    var result = evaluate(conditions[0], leafEvaluator);
    return result === null ? null : !result;
  }
  return null;
}
function notEvaluator ( conditions , leafEvaluator ) { if ( conditions . length > 0 ) { var result = evaluate ( conditions [ 0 ] , leafEvaluator ) ; return result === null ? null : ! result ; } return null ; }
Evaluates an array of conditions as if the evaluator had been applied
to a single entry and NOT was applied to the result.
@param  {Array}      conditions      Array of conditions ex: [operand_1]
@param  {Function}   leafEvaluator   Function which will be called to evaluate leaf condition values
@return {?Boolean}                   Result of evaluating the conditions. A return value of null
indicates that the conditions are invalid or unable to be
evaluated.
Evaluates an array of conditions as if the evaluator had been applied to a single entry and NOT was applied to the result .