```ruby
class Scrabble
  attr_reader :word
  def initialize(word)
    @word = word&.downcase
  end

  def score
    return 0 if word_invalid
    points = 0
    word.each_char do |char|
      points += CHAR_POINTS[char]
    end
    points
  end

  def self.score(word)
    points = 0
    word.each_char do |char|
      points += CHAR_POINTS[char]
    end
    points
  end

  def word_invalid
    word.nil? || word == '' || word == " \t\n"
  end

  CHAR_POINTS = {
    'a' => 1,
    'b' => 3,
    'c' => 3,
    'd' => 2,
    'e' => 1,
    'f' => 4,
    'g' => 2,
    'h' => 4,
    'i' => 1,
    'j' => 8,
    'k' => 5,
    'l' => 1,
    'm' => 3,
    'n' => 1,
    'o' => 1,
    'p' => 3,
    'q' => 10,
    'r' => 1,
    's' => 1,
    't' => 1,
    'u' => 1,
    'v' => 4,
    'w' => 4,
    'x' => 8,
    'y' => 4,
    'z' => 10
  }

end
```

Change constant name and call score in self.score
user
```ruby
class Scrabble
  attr_reader :word
  def initialize(word)
    @word = word&.downcase
  end

  def score
    return 0 if word_invalid
    points = 0
    word.each_char do |char|
      points += TILE_POINTS[char]
    end
    points
  end

  def self.score(word)
    new(word).score
  end

  def word_invalid
    word.nil? || word == '' || word == " \t\n"
  end

  TILE_POINTS = {
    'a' => 1,
    'b' => 3,
    'c' => 3,
    'd' => 2,
    'e' => 1,
    'f' => 4,
    'g' => 2,
    'h' => 4,
    'i' => 1,
    'j' => 8,
    'k' => 5,
    'l' => 1,
    'm' => 3,
    'n' => 1,
    'o' => 1,
    'p' => 3,
    'q' => 10,
    'r' => 1,
    's' => 1,
    't' => 1,
    'u' => 1,
    'v' => 4,
    'w' => 4,
    'x' => 8,
    'y' => 4,
    'z' => 10
  }

end
```
assistant