code: func (c *Cell) FormattedValue() (string, error) {
  	fullFormat := c.getNumberFormat()
  	returnVal, err := fullFormat.FormatValue(c)
  	if fullFormat.parseEncounteredError != nil {
  		return returnVal, *fullFormat.parseEncounteredError
  	}
  	return returnVal, err
  }
docs: // FormattedValue returns a value, and possibly an error condition
  // from a Cell.  If it is possible to apply a format to the cell
  // value, it will do so, if not then an error will be returned, along
  // with the raw value of the Cell.