code: function _lookupValueInPair(pair) {
    var keyId = pair[0];
    var value = pair[1];
    return Bluebird.all([
      keyId,
      this.lookupCriteriaValues(value, keyId)
    ]);
  }
docs: Query DFP for the value id of a key value pair.
  
  @param  {Array} pair [0] The id of a key.
  [1] The name of a value.
  @return {Promise}    Resolves with an Array
  [0] The dfp id of the key passed in (unchanged).
  [1] The dfp id of value passed in.