void addRandomMasses() {
        for (int i = 0; i < grammar.getNumberOfRandomMasses(); i++) {
            Range expansionRangeX = grammar.getExpansionRangeX();
            Range expansionRangeY = new Range(grammar.shoulder.getY(), grammar.hand.getY());            
            Mass randomMass = createMass(expansionRangeX, expansionRangeY);
            
            
            if (randomMass.getY() > grammar.hand.getY()) {
                randomMass = new Mass(randomMass.getX(), grammar.hand.getY(), randomMass.getType());
            }

            grammar.getGraph().addMasses(randomMass);
        }
    }