driver-core/src/main/com/mongodb/bulk/IndexRequest.java
public IndexRequest textVersion(final Integer textVersion) {
        if (textVersion != null) {
            isTrueArgument("textVersion must be 1, 2 or 3", VALID_TEXT_INDEX_VERSIONS.contains(textVersion));
        }
        this.textVersion = textVersion;
        return this;
    }
public IndexRequest textVersion(final Integer textVersion) {
        if (textVersion != null) {
            isTrueArgument("textVersion must be 1, 2 or 3", VALID_TEXT_INDEX_VERSIONS.contains(textVersion));
        }
        this.textVersion = textVersion;
        return this;
    }
Set the text index version number.

@param textVersion the text index version number.
@return this