docs: void accept(final double value) {
  		++_n;
  
  		final double n = _n;
  		final double d = value - _m1.value();
  		final double dN = d/n;
  		final double dN2 = dN*dN;
  		final double t1 = d*dN*(n - 1.0);
  
  		_m1.add(dN);
  		_m4.add(t1*dN2*(n*n - 3.0*n + 3.0))
  			.add(6.0*dN2*_m2.value() - 4.0*dN*_m3.value());
  		_m3.add(t1*dN*(n - 2.0) - 3.0*dN*_m2.value());
  		_m2.add(t1);
  	}