a = $a; $this->b = $b; $this->c = $c; } public function plus(self $specificity) : self { return new self($this->a + $specificity->a, $this->b + $specificity->b, $this->c + $specificity->c); } public function getValue() : int { return $this->a * self::A_FACTOR + $this->b * self::B_FACTOR + $this->c * self::C_FACTOR; } public function compareTo(self $specificity) : int { if ($this->a !== $specificity->a) { return $this->a > $specificity->a ? 1 : -1; } if ($this->b !== $specificity->b) { return $this->b > $specificity->b ? 1 : -1; } if ($this->c !== $specificity->c) { return $this->c > $specificity->c ? 1 : -1; } return 0; } }