function isSafeInteger( x ) {
	return (
		x >= MIN_SAFE_INTEGER &&
		x <= MAX_SAFE_INTEGER &&
		isInteger( x )
	);
}
Tests if a finite double-precision floating-point number is a safe integer.

@param {number} x - value to test
@returns {boolean} boolean indicating whether the value is a safe integer

@example
var bool = isSafeInteger( 1.0 );
// returns true

@example
var bool = isSafeInteger( 2.0e200 );
// returns false

@example
var bool = isSafeInteger( 3.14 );
// returns false