Returns the string representation of the {@code Object} argument.
@param obj an {@code Object}.
@return if the argument is {@code null}, then a string equal to
{@code "null"}; otherwise, the value of
{@code obj.toString()} is returned.
@see java.lang.Object#toString()
Returns the string representation of the {@code Object} argument.
@param obj an {@code Object}. @return if the argument is {@code null}, then a string equal to {@code "null"}; otherwise, the value of {@code obj.toString()} is returned. @see java.lang.Object#toString()