function iterIncrspace( start, stop, increment ) {
	var iter;
	var incr;
	var FLG;
	var N;
	var i;

	if ( !isNumber( start ) || isnan( start ) ) {
		throw new TypeError( format( 'invalid argument. First argument must be a number. Value: `%s`.', start ) );
	}
	if ( !isNumber( stop ) || isnan( stop ) ) {
		throw new TypeError( format( 'invalid argument. Second argument must be a number. Value: `%s`.', stop ) );
	}
	if ( arguments.length > 2 ) {
		if ( !isNumber( increment ) || isnan( increment ) ) {
			throw new TypeError( format( 'invalid argument. Third argument must be a number. Value: `%s`.', increment ) );
		}
		incr = increment;
	} else {
		incr = DEFAULT_INCREMENT;
	}
	N = ceil( (stop-start)/incr );
	i = -1;

	// Create an iterator protocol-compliant object:
	iter = {};
	setReadOnly( iter, 'next', next );
	setReadOnly( iter, 'return', end );

	// If an environment supports `Symbol.iterator`, make the iterator iterable:
	if ( iteratorSymbol ) {
		setReadOnly( iter, iteratorSymbol, factory );
	}
	return iter;

	/**
	* Returns an iterator protocol-compliant object containing the next iterated value.
	*
	* @private
	* @returns {Object} iterator protocol-compliant object
	*/
	function next() {
		i += 1;
		if ( FLG || i >= N ) {
			return {
				'done': true
			};
		}
		return {
			'value': start + (i*incr),
			'done': false
		};
	}

	/**
	* Finishes an iterator.
	*
	* @private
	* @param {*} [value] - value to return
	* @returns {Object} iterator protocol-compliant object
	*/
	function end( value ) {
		FLG = true;
		if ( arguments.length ) {
			return {
				'value': value,
				'done': true
			};
		}
		return {
			'done': true
		};
	}

	/**
	* Returns a new iterator.
	*
	* @private
	* @returns {Iterator} iterator
	*/
	function factory() {
		return iterIncrspace( start, stop, incr );
	}
}
Returns an iterator which returns evenly spaced numbers according to a specified increment.

@param {number} start - starting value (inclusive)
@param {number} stop - stopping value (exclusive)
@param {number} [increment=1] - increment
@throws {TypeError} first argument must be a number
@throws {TypeError} second argument must be a number
@throws {TypeError} third argument must be a number
@returns {Iterator} iterator

@example
var iter = iterIncrspace( 0, 100, 2 );

var v = iter.next().value;
// returns 0

v = iter.next().value;
// returns 2

v = iter.next().value;
// returns 4

// ...