code: public MarketEquilibrium clean() {
  
          final PrimitiveMatrix tmpAssetVolatilities = FinanceUtils.toVolatilities(myCovariances, true);
          final PrimitiveMatrix tmpCleanedCorrelations = FinanceUtils.toCorrelations(myCovariances, true);
  
          final PrimitiveMatrix tmpCovariances = FinanceUtils.toCovariances(tmpAssetVolatilities, tmpCleanedCorrelations);
  
          return new MarketEquilibrium(myAssetKeys, tmpCovariances, myRiskAversion);
      }
docs: Equivalent to copying, but additionally the covariance matrix will be cleaned of negative and very
  small eigenvalues to make it positive definite.