code: function (format) {
              _validFormat(format);
      
              var m = _regexDecFormat.exec(format);
              if (m !== null)
                  return (  (typeof m[3] === 'string') ? m[3].length : 0 )
                       + ( (m[4] === '%')              ? 2           : 0 );
              
              else {
                  m = _regexFracFormat.exec(format);
                  if (m !== null)
                      return _getPrecision(1 / parseInt(m[2], 10));
              }
              
              throw "IllegalArgumentException: format is not recognized (" + format + ")";
          }
docs: Returns the number of decimals necessary to do
  math operations accurately with specified 'format'.
  
  @param format {String}
  @return {Integer} Number of decimals, >= 0