You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: sine_waves_generator.rb
    path of file: ./repos/geo_pattern/lib/geo_pattern/structure_generators
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module GeoPattern
  module StructureGenerators
    class SineWavesGenerator < BaseGenerator
      private

      attr_reader :period, :amplitude, :wave_width

      def after_initialize
        @period = map(hex_val(0, 1), 0, 15, 100, 400).floor
        @amplitude = map(hex_val(1, 1), 0, 15, 30, 100).floor
        @wave_width = map(hex_val(2, 1), 0, 15, 3, 30).floor

        self.height = wave_width * 36
        self.width = period
      end

      def generate_structure
        36.times do |i|
          val = hex_val(i, 1)
          opacity = opacity(val)
          fill = fill_color(val)
          x_offset = period / 4 * 0.7

          styles = {
            "fill" => "none",
            "stroke" => fill,
            
    
      def generate_structure
        36.times do |i|
          val = hex_val(i, 1)
          opacity = opacity(val)
          fill = fill_color(val)
          x_offset = period / 4 * 0.7

          styles = {
            "fill" => "none",
            "stroke" => fill,
            "style" => {
              "opacity" => opacity,
              "stroke-width" => "#{wave_width}px"
            }
          }

          str = "M0 #{amplitude} C #{x_offset} 0, #{period / 2 - x_offset} 0, #{period / 2} #{amplitude} S #{period - x_offset} #{amplitude * 2}, #{period} #{amplitude} S #{period * 1.5 - x_offset} 0, #{period * 1.5}, #{amplitude}"

          svg.path(str, styles.merge("transform" => "translate(-#{period / 4}, #{wave_width * i - amplitude * 1.5})"))
          svg.path(str, styles.merge("transform" => "translate(-#{period / 4}, #{wave_width * i - amplitude * 1.5 + wave_width * 36})"))
        end

        svg
      end