function first( str, n ) {
	return str.substring( 0, n );
}
Returns the first `n` UTF-16 code units of a string.

@param {string} str - input string
@param {NonNegativeInteger} n - number of UTF-16 code units to return
@returns {string} output string

@example
var out = first( 'last man standing', 1 );
// returns 'l'

@example
var out = first( 'presidential election', 1 );
// returns 'p'

@example
var out = first( 'JavaScript', 1 );
// returns 'J'

@example
var out = first( 'Hidden Treasures', 1 );
// returns 'H'