SqlStreamInput/Output use TransportVersion from a read-in Version constant. We need to remove the useage of `transportVersion` field
server/src/main/java/org/elasticsearch/TransportVersion.java
public int compareTo(TransportVersion other) {
        return Integer.compare(this.id, other.id);
    }
    public static TransportVersion fromString(String str) {
        return TransportVersion.fromId(Integer.parseInt(str));
    }
    @Override
    public String toString() {
        return Integer.toString(id);
    }
    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        TransportVersion version = (TransportVersion) o;
        if (id != version.id) {
            return false;
        }
        return true;
    }
    @Override
    public int hashCode() {
        return id;
    }
}