code: function(oExpression, sIdentifierName) {
                     /**
                      * The prefixed String value that is equivalent to the
                      * sequence of terminal symbols that constitute the
                      * encountered identifier name.
                      * @type {string}
                      */
                     var sPrefixed = EValuePrefixes.S_STRING + sIdentifierName;
  
                     return oSolutionBest.oPrimitiveValues.hasOwnProperty(
                         sPrefixed) &&
                         oSolutionBest.oPrimitiveValues[sPrefixed].nSaving > 0 ?
                         ['sub',
                          oWalker.walk(oExpression),
                          ['name',
                           oSolutionBest.oPrimitiveValues[sPrefixed].sName]] :
                         ['dot', oWalker.walk(oExpression), sIdentifierName];
                   }
docs: If the String value that is equivalent to the sequence of
  terminal symbols that constitute the encountered identifier
  name is worthwhile, a syntactic conversion from the dot
  notation to the bracket notation ensues with that sequence
  being substituted by an identifier name to which the value
  is assigned.
  Applies to property accessors that use the dot notation.
  @param {!TSyntacticCodeUnit} oExpression The nonterminal
  MemberExpression.
  @param {string} sIdentifierName The identifier name used as
  the property accessor.
  @return {!Array} A syntactic code unit that is equivalent to
  the one encountered.
  @see TPrimitiveValue#nSaving