function Results( pValue, alpha, statistic, df ) {
	if ( !(this instanceof Results) ) {
		return new Results( pValue, alpha, statistic, df );
	}
	this._pValue = pValue;
	this._alpha = alpha;
	this._statistic = statistic;
	this._df = df;
	return this;
}
Returns a results object.

@private
@constructor
@param {number} pValue - p-value
@param {number} alpha - significance
@param {number} statistic - test statistic
@param {(number|null)} df - degrees of freedom
@returns {Results} results object

@example
var res = new Results( 0.0406, 0.05, 9.9901, 4 );
// returns <Results>