code: @Override
      public boolean setProductCoefficients(Double[] coefficients) {
          boolean result = products.setMultipliers(coefficients);
          notifyChanged();
          return result;
      }
docs: Sets the coefficient of the products.
  
  @param   coefficients An array of double's containing the coefficients of the products
  @return  true if coefficients have been set.
  @see     #getProductCoefficients