code: function translateValue(sceneDrawGroup, ccssProperty, ccssValue) {
      if (ccssProperty.indexOf('comp-op') >= 0) {
          switch (ccssValue) {
              case 'src-over':
                  return 'overlay';
              case 'plus':
                  return 'add';
              default:
                  return ccssValue;
          }
      }
      if (referenceCSS[ccssProperty].type === 'color') {
          return getColorFromLiteral(sceneDrawGroup, ccssValue, ccssProperty.indexOf('fill') >= 0);
      }
      if (ccssProperty.indexOf('width') >= 0) {
          ccssValue += 'px';
      }
      if (ccssProperty.indexOf('allow-overlap') >= 0) {
          ccssValue = !ccssValue;
      }
      return ccssValue;
  }
docs: Translates a ccssValue from the reference standard to the Tangram standard