code: function drawValueTextShadow(context, options, offset, blur) {
      if (options.valueTextShadow) {
          context.shadowOffsetX = offset;
          context.shadowOffsetY = offset;
          context.shadowBlur = blur;
          context.shadowColor = options.colorValueTextShadow;
      }
  }
docs: /* istanbul ignore next: private, not testable 
  Declares to drow value text shadow if configured
  
  @param context
  @param options
  @param offset
  @param blur