function accumulator( x ) {
		var ax;
		if ( arguments.length === 0 ) {
			if ( FLG === false ) {
				return null;
			}
			minmax[ 0 ] = min; // Why? Because we cannot guarantee someone hasn't mutated the output array
			minmax[ 1 ] = max;
			return minmax;
		}
		FLG = true;
		if ( isnan( x ) ) {
			min = x;
			max = x;
		} else {
			ax = abs( x );
			if ( ax < min ) {
				min = ax;
			}
			if ( ax > max ) {
				max = ax;
			}
		}
		minmax[ 0 ] = min;
		minmax[ 1 ] = max;
		return minmax;
	}
If provided a value, the accumulator function returns updated minimum and maximum absolute values. If not provided a value, the accumulator function returns the current minimum and maximum absolute values.

@private
@param {number} [x] - input value
@returns {(ArrayLikeObject|null)} output array or null