function isWellFormedString( str ) {
	return (
		isString.isObject( str ) &&
		isWellFormed( str.valueOf() )
	);
}
Tests if a string is a well-formed string object.

@param {string} str - input string
@returns {boolean} boolean indicating if a string is a well-formed string object

@example
var bool = isWellFormedString( '\uDC00' );
// returns false

@example
var bool = isWellFormedString( new String( '' ) );
// returns true