function getStyleValue(value) {
  if (!goog.isObject(value)) {
    throw new Error(
        SafeHtml.ENABLE_ERROR_MESSAGES ?
            'The "style" attribute requires goog.html.SafeStyle or map ' +
                'of style properties, ' + (typeof value) + ' given: ' + value :
            '');
  }
  if (!(value instanceof SafeStyle)) {
    // Process the property bag into a style object.
    value = SafeStyle.create(value);
  }
  return SafeStyle.unwrap(value);
}
Gets value allowed in "style" attribute.
@param {!SafeHtml.AttributeValue} value It could be SafeStyle or a
    map which will be passed to SafeStyle.create.
@return {string} Unwrapped value.
@throws {!Error} If string value is given.
@private