function validate( a, b ) {
	if ( !isInteger( a ) || isnan( a ) ) {
		return new TypeError( format( 'invalid argument. First argument must be an integer and not NaN. Value: `%s`.', a ) );
	}
	if ( !isInteger( b ) || isnan( b ) ) {
		return new TypeError( format( 'invalid argument. Second argument must be an integer and not NaN. Value: `%s`.', b ) );
	}
	if ( a > b ) {
		return new RangeError( format( 'invalid argument. Minimum support must be less than or equal to maximum support. Value: `[%d, %d]`.', a, b ) );
	}
	return null;
}
Validates values provided for minimum and maximum support.

@private
@param {integer} a - minimum support
@param {integer} b - maximum support
@returns {(Error|null)} error or null

@example
var err = validate( 1, 20 );
if ( err ) {
    throw err;
}