types/src/main/java/com/google/common/html/types/SafeStyleBuilder.java
public SafeStyleBuilder backgroundAttachmentAppend(String value, String... otherValues) {
    appendToProperty("background-attachment", sanitizeAndJoinEnumValues(value, otherValues));
    return this;
  }
public SafeStyleBuilder backgroundAttachmentAppend(String value, String... otherValues) {
    appendToProperty("background-attachment", sanitizeAndJoinEnumValues(value, otherValues));
    return this;
  }
Appends {@code values} to the {@code background-attachment} property. Values will be comma
separated.

<p>The values must consist of only ASCII alphabetic or '-' characters. A non-conforming value
will be replaced with {@link #INNOCUOUS_PROPERTY_STRING}.

@see "https://developer.mozilla.org/en-US/docs/Web/CSS/background-attachment"