Run3 scala fluent builder pattern

Fluent Builder Implementation

The TokenizerBuilder should provide a functional and fluent interface.

1. State Management: The builder can maintain an internal state using a private var (encapsulated) or by returning a new version of the builder case class with updated fields.
2. Method Chaining: Ensure methods return this.type (for mutable builders) or a new instance of the builder (for immutable builders). This allows the user to chain calls like .withType(...).withModel(...).
3. The Build Method: Provide a build() method that validates the current state and instantiates the appropriate BaseTokenizer implementation.

Pattern Structure

class TokenizerBuilder {
  private var tokenizerType: String = _
  
  def setType(t: String): this.type = {
    this.tokenizerType = t
    this
  }
  
  def build(): BaseTokenizer = {
    // Logic to return specific implementation based on tokenizerType
  }
}

This pattern provides a clear, type-safe API for constructing complex objects while hiding the instantiation logic of the specific tokenizer subclasses.