code: public RandomVariableInterface getCovariance(double time, int component1, int component2, RandomVariableInterface[] realizationAtTimeIndex) {
  		int timeIndex = timeDiscretization.getTimeIndex(time);
  		if(timeIndex < 0) {
  			timeIndex = Math.abs(timeIndex)-2;
  		}
  
  		return getCovariance(timeIndex, component1, component2, realizationAtTimeIndex);
  	}
docs: Returns the instantaneous covariance calculated from factor loadings.
  
  @param time The time <i>t</i> at which covariance is requested.
  @param component1 Index of component <i>i</i>.
  @param component2  Index of component <i>j</i>.
  @param realizationAtTimeIndex The realization of the stochastic process.
  @return The instantaneous covariance between component <i>i</i> and  <i>j</i>.