code: function PaperWave(options) {
          this.color = _window.getComputedStyle(options.$).color;
          this.containerRect = new ElementRect(options.$);
          this.recenters = options.recenters || false;
          this.center = options.center || false;
          this.initialOpacity = options.initialOpacity || 0.25;
          this.opacityDecayVelocity = options.opacityDecayVelocity || 0.8;
          this.$wave = _doc.createElement('div');
          this.$wave.classList.add('paper-ripple__wave');
          this.$wave.style.backgroundColor = this.color;
          this.$ = _doc.createElement('div');
          this.$.classList.add('paper-ripple__wave-container');
          this.$.appendChild(this.$wave);
          this.resetDefaults();
      }
docs: Initializes a new instance of the `PaperWave` class with the specified `PaperRipple` instance.